Low-level Resistance Research Articles

Antimicrobial Susceptibility Profiles of Salmonella spp. Isolates from Clinical Cases of Waterfowl in Hungary Between 2022 and 2023

The global spread of antimicrobial resistance is one of the most significant challenges of the 21st century. The waterfowl sector is an economically decisive part of the poultry industry, yet it remains under-researched, and its antibiotic usage is less monitored. Our study aimed to determine the antimicrobial susceptibility of avian pathogenic Salmonella strains, which are still prevalent in ducks and geese, against antibiotics critical for both animal and human health, and to compare these findings with human resistance data. We analyzed 71 Salmonella strains, collected by the National Reference Laboratory from samples originating from 29 settlements across Hungary between 2022 and 2023, using the minimum inhibitory concentration (MIC) method. Notably, the duck strains (n = 52) exhibited 57.7% resistance to potentiated sulfonamides, 28.8% resistance to doxycycline, and 25% resistance to cefotaxime. Among the geese strains (n = 19), 52.6% showed resistance to potentiated sulfonamides, followed by 26.3% resistance to doxycycline and amoxicillin–clavulanic acid, and 15.8% resistance to cefotaxime, ceftiofur, and ceftriaxone. When compared to human resistance data, we found significantly lower resistance levels for amoxicillin in ducks (20.0%) and geese (8.3%) in the Dél-Alföld region, compared to ampicillin resistance in human samples (45.4%), in which amoxicillin analog is an antibiotic in human medicine. Resistance to ciprofloxacin was only observed in ducks (2.0%), whereas pefloxacin resistance in human medicine was notably higher (22.3%). Overall, the results for the waterfowl sector in the Dél-Alföld region of Hungary align with the international literature in several aspects. Further investigation using next-generation sequencing to identify the genetic basis of multi-resistant strains is warranted.

Monitoring the insecticide susceptibility of a newly introduced invasive species, Tuta absoluta (Meyrick), in China

The South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a newly introduced invasive destructive pest that poses a major threat to tomato production in China. Chemical control is a predominantly measure for controlling this pest. Monitoring of insecticide efficacy is the basic tool for proactive evidence-based resistance management. As a new invasive species, the insecticide susceptibility of T. absoluta to main insecticides has been uncertainty so far in China. Here, we investigated the insecticide susceptibilities of seven populations (Yunnan, Guizhou, Sichuan, Gansu, Inner Mongolia, Shanxi and Xinjiang) of T. absoluta across China. The response of these populations was evaluated through laboratory bioassays with the main insecticides used for T. absoluta control: chlorantraniliprole, chlorpyrifos, indoxacarb, emamectin benzoate, spinosad and Bacillus thuringiensis. Analysis of the results showed the largest LC50 values for chlorpyriphos were generated in populations from Shanxi and Yunnan, resulting in 22.59-fold and 11-fold differences, respectively, compared with the values generated in the most susceptible population (Inner Mongolia). The LC50 values observed for chlorantraniliprole in Shanxi and Gansu were 24.66-fold and 20.83-fold greater, respectively, than the LC50 value observed in the most susceptible population (Guizhou). However, almost all populations of T. absoluta presented low resistance levels to indoxacarb, emamectin benzoate, spinosad and B. thuringiensis. Our study sheds light on most insecticides can provide sufficient control of T. absoluta in China, however, scientific selection and use of insecticides, such as rotational use of insecticides of different modes of action classes, also need to adopt as soon as possible, because a moderate level of resistance has already been observed somewhere on chlorantraniliprole and chlorpyrifos.

ПСИХОЛОГІЧНІ ОСОБЛИВОСТІ ПРОЯВУ КОПІНГ-СТРАТЕГІЙ СТУДЕНТІВ З РІЗНИМ РІВНЕМ СТРЕСОСТІЙКОСТІ

Ukrainian society and every Ukrainian family is currently experiencing social and psychological difficulties as a result of the Russian invasion of Ukraine. All this creates a significant number of stressors for the population. Martial law, hostilities, forced changes in living conditions, and constant stress cause people to experience difficulties in maintaining psychological comfort. Therefore, the problem of optimal choice of coping strategies, especially by students, is becoming particularly relevant. The article deals with the issue of individual's choice of behaviour coping strategies. The special significance of the formation and development of this phenomenon in the participants of the educational process of a higher education institution is emphasized. In particular, the emphasis is placed on the difficulties that students are currently facing, namely the consequences of quarantine restrictions, a sense of isolation, internal discomfort and general psycho-emotional stress caused by the martial law in our country. The article focuses on coping strategies as a subconscious means of psychological defence that shapes human behaviour in certain conditions. A theoretical analysis is carried out and meanings of the following concepts are indicated: «coping», «coping strategy», «coping behaviour» and «coping resources», as well as an analysis of the peculiarities of making behavioural choices in certain conditions. The main strategies of behaviour in a stressful situation and the main approaches to the study of coping behaviour and behavioural strategies are analysed. The article reflects empirical indicators of the ratio of dominant coping strategies at different levels of stress resistance. A correlation between the level of stress resistance and coping strategies has been established: with a low level of stress resistance, passive coping strategy dominates; in the presence of a high level - active coping strategies.

Detection and functional validation of point mutations in acetylcholinesterase-1 associated with organophosphate resistance in field populations of Helicoverpa armigera.

Point mutations in the acetylcholinesterase-1 gene (ace-1) have been associated with resistance to OPs in many insects. However, the presence and function of ace-1 mutations associated with OP resistance in Helicoverpa armigera (Lepidoptera: Noctuidae), a significant lepidopteran pest damaging a wide range of crops, remain largely unexplored. This study investigated resistance to the OP insecticide phoxim in 12 field populations of H. armigera from northern China in 2022, revealing low levels of resistance (2.5- to 6.7-fold). Using an amplicon sequencing approach, we screened for ace-1 mutations in 13,874 moths collected from 114 populations collected between 2006 and 2022. We found 3 amino acid substitutions (A201S, G227E, and F290V) potentially related to OP resistance. The mean frequencies of A201S, G227E, and F290V mutations were 0.0032, 0.0001, and 0.0001, respectively. To assess these mutations' role in OP resistance, we expressed wild-type and mutant AChE1 proteins in Sf9 cells. Biochemical characterization revealed a 3.1-fold and 3.3-fold increase in the I50 of chlorpyrifos-oxon for A201S and F290V mutants compared to the wild-type enzyme, correlating with a 2.9-fold and 2.7-fold decrease in the Ki value. No enzyme activity was observed in the G227E mutant, indicating that only A201S and F290V confer insensitivity to chlorpyrifos-oxon. Our study demonstrates that amplicon sequencing is an effective method for large-scale screening of resistance-associated point mutations in field populations of H. armigera and potentially other insect pests. It also identifies A201S and F290V in AChE1 as potential point mutations conferring OP resistance in field populations of H. armigera.

Novel sequence types and low levels of antimicrobial resistance associated with clinical mastitis in sheep flocks across Scotland.

This research paper aimed to demonstrate that mammary secretions provided by sheep farmers across Scotland from cases of clinical mastitis are free from environmental contamination, as well as to provide information on the major bacterial causes of disease and levels of antimicrobial resistance. Mastitis represents one of most significant diseases of small ruminant production worldwide. Staphylococcus aureus, Mannheimia haemolytica, Streptococcus uberis and coagulase-negative Staphylococcal species are common pathogens isolated from cases of sheep mastitis. Sampling kits supplied to 23 farms provided 33 samples for bacteriology, antimicrobial susceptibility testing and genetic analysis. Of the bacterial isolates identified, 60% were S. aureus, 23% M. haemolytica and 7% coagulase-negative staphylococci. Low levels of antimicrobial resistance were identified in the S. aureus isolates which provided novel multi-locus sequence types. In conclusion, this proof-of-concept survey demonstrated that mammary secretions free from environmental contamination may be provided by sheep farmers. It also provided data on the prevalence of antimicrobial resistance associated with clinical mastitis in sheep and will inform on the scale required for larger surveys aiming to improve current strategies for mastitis control in sheep flocks across the UK.

Study in murine model: Is there a relationship between presbycusis and frailty?

Age-related hearing loss (ARHL) or Presbycusis is the most frequent sensory deficiency in older adults and is associated with comorbidities, such as falls, cognitive decline, and frailty. Frailty is related to poor health outcomes in old age. Recent research suggested that ARHL may be a potentially modifiable risk factor for frailty, although inconclusive. The use of animal models to study the correlation between ARHL and frailty is important to test future interventions to be translated into clinical practice. The aim of this study was to determine if there is an association between ARHL and frailty in experimental animals based on the human frailty phenotype. This research studied male and female C57Bl/6J mice, at different ages (6, 14, and 22 months). Auditory steady-state responses (ASSR) threshold shifts were measured at different frequencies. To assess frailty status, we were based on the "Valence Score" which consists of measuring: weakness, weight loss, low level of activity, slowness, and little resistance. We found that hearing is significantly lower in older age groups. The mice become frail as they age. The worsening in ASSR threshold shifts with age correlates significantly with an increasing frailty. No significant differences were found between both sexes. Our research is, to our knowledge, the first carried out in experimental animals to establish the association between ARHL and frailty, which would provide a useful tool to evaluate future interventions in mice before translating them into clinical practice.

Bacterial profile and antimicrobial susceptibility patterns of isolates from inanimate objects used by healthcare professionals at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.

Healthcare-associated infections occur in patients under medical care, which is a major public health issue in hospitals worldwide. The prevalence is two to three folds higher in developing countries compared to developed countries. Inanimate objects used by healthcare professionals such as gowns, mobile phones, and stethoscopes are highly prone to bacterial contamination from the healthcare setting. In Ethiopia, there is a paucity of published data on the bacterial profile and susceptibility patterns of an isolates. To determine the bacterial profile and antimicrobial susceptibility patterns from inanimate objects used by healthcare professionals and associated factors at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia. A cross-sectional study was conducted at Debre Markos Comprehensive Specialized Hospital from inanimate objects from April 10, 2023 to June 30, 2023 using simple random sampling technique with lottery method. Socio-demographic data was collected using a structured questionnaire. A swab sample from healthcare professionals' gowns, mobile phones, and stethoscopes were collected and inoculated onto blood agar, chocolate and MacConkey agar. Isolates were identified and characterized by colony morphology, Gram staining and biochemical tests. Antimicrobial susceptibility testing was performed in all isolates by the disk diffusion technique on Muller Hinton agar according to CLSI, 2022 guidelines. Data was entered into EPI-Data and analyzed using SPSS version 25. Logistic regression model was used. Variables with p-value ≤ 0.25 in bivariable logistic regression was fitted to multivariate logistic regression analysis. A p-value of ≤ 0.05 with 95%CI was considered statistically significant. A total of 376 healthcare professionals' inanimate objects were included from 191 study participants. Overall, 60.1% (226/376) (95%CI: 55.1-65) inanimate objects were contaminated. The proportion of bacterial contamination was (65.1%; 82/126), (60.3%; 76/126) and (54.8%; 68/124) for mobile phones, gowns and stethoscopes, respectively. Staphylococcus aureus was the most frequent isolate accounting (22.1%; 83/376) followed by Staphylococcus epidermidis (17.0%; 64/376), Escherichia coli (8.8%; 33/376) and Pseudomonas aeruginosa (4.9%; 18/376). Working in gynecology/ obstetrics wards (AOR: 8.69; 95%CI: 1.09-69.41, P = 0.041), did not disinfect mobile phones (AOR: 2.69; 95%CI: 1.15-6.25; P = 0.021) and stethoscopes regularly (AOR: 3.06, 95%CI: 1.23-7.59; P = 0.016), carry mobile phones with patient care materials (AOR: 2.72; 95%CI: 1.18-6.29, P = 0.019) and not taken infection prevention training (AOR:3.91; 95%CI:1.71-8.93; P = 0.001) were significantly associated with bacterial contamination.Most Gram-negative bacteria were resistant to ampicillin, trimethoprim-sulfamethoxazole and amoxacilline-clavunic acid, while Gram-positive isolates showed high level of resistant to penicillin. On the other hand, meropenem, for Gram-negative and clindamycin for Gram-positive bacteria showed lower level of resistance. Multidrug resistance among Gram-positive and Gram-negative bacteria were (62.6%; 92/147) and (75.3%; 64/85), respectively with over all MDR (67.2%, 156/232). Inanimate objects commonly used by healthcare professionals are important sources of bacterial contamination. S. aureus, S. epidermidis and E. coli were the predominant isolates. Most Gram-negative bacteria were resistant to ampicillin while Gram-positive isolates showed high level of resistant to penicillin. All healthcare professionals should regularly disinfect their inanimate objects to prevent bacterial colonization and potential spread of infection.

Murine colon cancer derived cells exhibit heterogeneous resistance profiles against an oncolytic virus

Oncolytic virotherapy has shown efficacy in various animal models and a few human cancers. However, there are still significant limitations for the implementation of these therapies. One such limitation is the emergence of cellular resistances, which may appear rapidly considering the high genetic heterogeneity of most tumors. We previously showed that cellular resistance to an oncolytic virus can be mediated by the chronic activation of innate immunity. Here, we explored the existence of additional resistance mechanisms in murine colon cancer-derived cells. For this purpose, we isolated two cellular clones that were resistant to the oncolytic virus VSV-D51. While one of the clones showed a strong resistance profile associated with increased cytokine-mediated antiviral responses, the other clone showed a lower level of resistance that involves cytoskeletal reorganization, signaling by small GTPases, and cell structural changes. These results demonstrate the capacity of tumor cells to deploy heterogeneous mechanisms of resistance to oncolytic viruses.

An arylsulfonamide that targets cell wall biosynthesis in Mycobacterium tuberculosis.

We investigated the mechanism of action of an arylsulfonamide with whole-cell activity against Mycobacterium tuberculosis. We newly synthesized the molecule and confirmed it had activity against both extracellular and intracellular bacilli. The molecule had some activity against HepG2 cells but maintained some selectivity. Bacterial cytological profiling suggested that the mechanism of action was via disruption of cell wall synthesis, with similarities to an inhibitor of the mycolic acid exporter MmpL3. The compound induced expression from the IniB promoter and caused a boost in ATP production but did not induce reactive oxygen species. A mutation in MmpL3 (S591I) led to low-level resistance. Taken together, these data confirm the molecule targets cell wall biosynthesis with MmpL3 as the most probable target.

Longitudinal genomic surveillance of a UK intensive care unit shows a lack of patient colonisation by multi-drug-resistant Gram-negative bacterial pathogens.

Vulnerable patients in an intensive care unit (ICU) setting are at high risk of infection from bacteria including gut-colonising Escherichia coli and Klebsiella species. Complex ICU procedures often depend on successful antimicrobial treatment, underscoring the importance of understanding the extent of patient colonisation by multi-drug-resistant organisms (MDROs) in large UK ICUs. Previous work on ICUs globally uncovered high rates of colonisation by transmission of MDROs, but the situation in UK ICUs is less understood. Here, we investigated the diversity and antibiotic resistance gene (ARG) carriage of bacteria present in one of the largest UK ICUs at the Queen Elizabeth Hospital Birmingham (QEHB), focusing primarily on E. coli as both a widespread commensal and a globally disseminated multi-drug-resistant pathogen. Samples were taken during highly restrictive coronavirus disease 2019 (COVID-19) control measures from May to December 2021. Whole-genome and metagenomic sequencing were used to detect and report strain-level colonisation of patients, focusing on E. coli sequence types (STs), their colonisation dynamics and antimicrobial resistance gene carriage. We found a lack of multi-drug resistance (MDR) in the QEHB. Only one carbapenemase-producing organism was isolated, a Citrobacter carrying bla KPC-2. There was no evidence supporting the spread of this strain, and there was little evidence overall of nosocomial acquisition or circulation of colonising E. coli. Whilst 22 different E. coli STs were identified, only 1 strain of the pandemic ST131 lineage was isolated. This ST131 strain was non-MDR and was found to be a clade A strain, associated with low levels of antibiotic resistance. Overall, the QEHB ICU had very low levels of pandemic or MDR strains, a result that may be influenced in part by the strict COVID-19 control measures in place at the time. Employing some of these infection prevention and control measures where reasonable in all ICUs might therefore assist in maintaining low levels of nosocomial MDR.

Multidrug tolerance conferred by loss-of-function mutations in anti-sigma factor RshA of Mycobacterium abscessus.

Low-level drug resistance in noncanonical pathways can constitute steppingstones toward acquisition of high-level on-target resistance mutations in the clinic. To capture these intermediate steps in Mycobacterium abscessus (Mab), we performed classic mutant selection experiments with moxifloxacin at twofold its minimum inhibitory concentration (MIC) on solid medium. We found that low-level resistance emerged reproducibly as loss-of-function mutations in RshA (MAB_3542c), an anti-sigma factor that negatively regulates activity of SigH, which orchestrates a response to oxidative stress in mycobacteria. Since oxidative stress is generated in response to many antibiotics, we went on to show that deletion of rshA confers low to moderate resistance-by measure of MIC-to a dozen agents recommended or evaluated for the treatment of Mab pulmonary infections. Interestingly, this moderate resistance was associated with a wide range of drug tolerance, up to 1,000-fold increased survival of a ΔrshA Mab mutant upon exposure to several β-lactams and DNA gyrase inhibitors. Consistent with the putative involvement of the SigH regulon, we showed that addition of the transcription inhibitor rifabutin (RBT) abrogated the high-tolerance phenotype of ΔrshA to representatives of the β-lactam and DNA gyrase inhibitor classes. In a survey of 10,000 whole Mab genome sequences, we identified several loss-of-function mutations in rshA as well as non-synonymous polymorphisms in two cysteine residues critical for interactions with SigH. Thus, the multidrug multiform resistance phenotype we have uncovered may not only constitute a step toward canonical resistance acquisition during treatment but also contribute directly to treatment failure.

Targeting virulence of resistant Escherichia coli by the FDA-approved drugs sitagliptin and nitazoxanide as an alternative antimicrobial approach.

The spread of multidrug-resistant Escherichia coli in healthcare facilities is a global challenge. Hospital-acquired infections produced by Escherichia coli include gastrointestinal, blood-borne, urinary tract, surgical sites, and neonatal infections. Therefore, novel approaches are needed to deal with this pathogen and its rising resistance. The concept of attenuating virulence factors is an alternative strategy that might lead to low levels of resistance and combat this pathogen. A sub-inhibitory concentration (¼ MIC) of sitagliptin and nitazoxanide was used for phenotypic assessments of Escherichia coli virulence factors such as biofilm production, swimming motility, serum resistance, and protease production. Moreover, qRT-PCR was used to determine the impact of sub-MIC of the tested drugs on the relative expression levels of papC, fimH, fliC, kpsMTII, ompT_m, and stcE genes encoding virulence factors in Escherichia coli. Also, an in vivo model was conducted as a confirmatory test. Phenotypically, our findings demonstrated that the tested strains showed a significant decrease in all the tested virulence factors. Moreover, the genotypic results showed a significant downregulation in the relative expression levels of all the tested genes. Besides, the examined drugs were found to be effective in protecting mice against Escherichia coli pathogenesis. Sitagliptin and nitazoxanide exhibited strong anti-virulence activities against Escherichia coli. In addition, it is recommended that they might function as adjuvant in the management of Escherichia coli infections with either conventional antimicrobial agents or alone as alternative treatment measures.

Myocardial contractile function in the post-traumatic period of cardiac contusion in rats with different stress resistance: A preclinical experimental randomized trial

Background. Pathogenesis of cardiac contusion involves primary traumatic and secondary hypoxic mechanisms of myocardial contractile function depression as well as body reactions aimed at adapting to altered environment. A significant part of these reactions is realized in the context of stress. The intensity of the stress component in myocardial dysfunction is largely determined by the individual stress reactivity of the body. Objectives. To assess the contractile function and functional reserves of the myocardium of rats with a high and low level of stress resistance in the post-traumatic period of cardiac contusion. Methods. A preclinical experimental randomized trial involved 134 white mature nonlinear male rats weighing about 270 g. The animals were divided by sequentially performed Open Field and Porsolt Forced Swim tests into 2 groups: group 1 — animals with low stress resistance, group 2 — animals with high stress resistance. Within each group, the animals were randomized into control and experimental subgroups. In the experimental subgroups, 6, 12 and 24 hours after simulating cardiac contusion, the force and rate indicators of myocardial contractility were evaluated using the Fallen isolated heart model. The summary measures of the study included assessing the contractile force and rate of isolated hearts of rats with low and high stress resistance, particularly under conditions of high-frequency rhythm load (ranging from 4.0 to 8.3 Hz) during the post-traumatic period of cardiac contusion. Data analysis was performed using software packages MS Office 2013 (Microsoft Corporation, USA) and Statistica, v. 10 (StatSoft, USA). The differences were considered to be statistically significant at p < 0.05. Results. 6, 12 and 24 hours after simulating a cardiac contusion, contractile force and rate of isolated hearts decreased in group 1 and group 2. In low stress-resistant animals, immediately following the stabilization period and during high-frequency rhythm test, the contractility force and rate in isolated hearts were statistically significantly lower (p = 0.0008) compared to those recorded in highly stress-resistant individuals. During the stimulation of a high-frequency rhythm, isolated hearts in the experimental group revealed diastolic dysfunction at all time points. In highly stress-resistant animals, diastolic dysfunction occurred at a heart rate of 300 min-1 and above, whereas in low stress-resistant animals, it manifested at a heart rate of 240 min-1 and above. At the same heart rate, diastolic dysfunction in low stress-resistant animals was statistically significantly greater (p = 0.0008) compared to that of highly resistant animals. Conclusion. The post-traumatic period following experimental myocardial contusion is characterized by a reduction in the force and rate of myocardial contractility, as well as a decrease in functional reserves of the myocardium, regardless of stress resistance. High stress resistance is associated with better preservation of cardiac contractile function and contractility reserves, whereas low stress resistance correlates with a more pronounced degree of myocardial dysfunction and a significant reduction in functional reserves of the contused heart. Differences in the severity of contractile dysfunction under conditions of high and low body resistance to stress can be attributed to varying degrees of secondary myocardial damage in the contused area, resulting from the misbalance between stress-activating and stress-limiting mechanisms involved in the development of secondary damage.

Unraveling the mechanisms of multiple resistance across glyphosate and glufosinate in Eleusine indica

The herbicides glyphosate and glufosinate are commonly used in citrus and sugarcane orchards in Guangxi Province, China, wherein the C4 plant Eleusine indica (L.) Gaertn. is known to be a dominant weed species. However, high selection pressure has resulted in failure of control. In the present study, experiments were conducted to clarify resistance levels for the suspected populations and elucidate the mechanisms for multiple resistance. The resistance index to glyphosate was calculated for eight populations and ranged from 5.4 to 21.3, with a low-level shikimate content of 0.24–0.50 μg g−1. In addition, three populations showed low-level resistance to glufosinate, with a resistance index ranging from 2.6 to 3.9. The amplification of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene with a double-mutation T102I + P106S (TIPS) or a single-mutation (P106S and P106A) was observed in most populations. The target genes of glufosinate (GS1–1, GS1–2, and GS1–3) showed high-level expression, namely 145.5-fold that of susceptible plants. The content of EPSPS and glutamine synthetase (GS) protein in resistant plants can reach to 3.6 and 2.1 times higher than those in susceptible plants, respectively. The overexpression of the EPSPS gene with double (T102I + P106S) or single (P106S and P106A) mutations, plus the overexpression of GS1–1, GS1–2, and GS1–3, responded to multiple resistance mechanisms. Altogether, these results demonstrate that overexpression of GS1 is a novel form of resistant mechanism to glufosinate in weeds.

Estimating a national critical mineral security index in Indonesia using analytical hierarchy process

Critical minerals are key to guaranteeing energy security and economic stability in a nation. Indonesia, as the largest country in Southeast Asia, has significant reserves of critical minerals. The current circumstances, however, pose substantial challenges for Indonesia as it strives for self-sufficiency in various sectors. Indonesia must pay attention to its natural resource management, especially that of critical minerals. This study aims to present information on securing critical mineral resources in Indonesia by constructing a Critical Mineral Security Index (CMSI). This study used a quasi-qualitative method, wherein the Analytical Hierarchy Process (AHP) was used as the process of analysis. A total of four dimensions have been proposed in this study—availability, accessibility, technology-efficiency, and environmental, social, and governance (ESG) dimensions with a total of 29 indicators. The results of the AHP confirm that the security level of critical mineral resources in Indonesia is 5.57. The results indicate that the availability dimension has the highest weight compared to the other dimensions, equal to 47.6%. While the accessibility dimension has the lowest level of resistance. The government should, therefore, prioritize improving the indicators of accessibility dimensions. These results have policy implications for the energy and mineral sector in the future, to further reinforce energy and mineral security on a national scale, which may ultimately support transition energy in Indonesia and strengthen national defense.

Engineered Mycobacteriophage TM4::GeNL Rapidly Determines Bedaquiline, Pretomanid, Linezolid, Rifampicin, and Clofazimine Sensitivity in Mycobacterium tuberculosis Clinical Isolates.

Drug-resistant tuberculosis is a growing public health threat, and early characterization of the resistance phenotype is essential for guiding treatment and mitigating the high mortality associated with the disease. However, the slow growth rate of Mycobacterium tuberculosis, the causative agent of tuberculosis, necessitates several weeks for conventional culture-dependent drug susceptibility testing (DST). In addition, there are no widely available molecular diagnostic assays for evaluating resistance to newer tuberculosis drugs or drugs with complex resistance mechanisms. We have developed a luciferase-based reporter mycobacteriophage assay that can determine drug resistance within 48 hours. We engineered the TM4 mycobacteriophage to express green enhanced nanoluciferase (GeNL) cassette and optimized DST for bedaquiline, pretomanid, linezolid, clofazimine, and rifampicin using clinical M. tuberculosis isolates. To assess the feasibility of this assay, we conducted a proof-of-principle study using 53 clinical M. tuberculosis isolates. TM4::GeNL phage DST effectively distinguished between sensitive and resistant isolates for bedaquiline and rifampicin at a concentration of 0.125 μg/mL. Optimal differentiation between sensitive and resistant isolates for pretomanid, clofazimine, and linezolid was achieved at concentrations of 0.5 μg/mL, 0.25 μg/mL, and 1 μg/mL, respectively. Additionally, TM4::GeNL DST identified low-level rifampicin resistance in clinical isolates even though they were classified as sensitive by Mycobacteria Growth Indicator Tube DST. TM4::GeNL reporter phage DST offers a rapid method to identify M. tuberculosis drug resistance, including resistance to newer tuberculosis drugs.

Area-wide survey and monitoring of insecticide resistance in the brown planthopper, Nilaparvata lugens (Stål), from 2020 to 2023 in China

The brown planthopper (BPH), Nilaparvata lugens (Stål), is a notorious pest affecting Asian rice crops. The evolution of insecticide resistance in BPH has emerged as a significant challenge in effectively managing this pest. This study revealed the resistance status of BPH to nine insecticides in ten provinces and Shanghai City in China from 2020 to 2023. Monitoring results showed that the resistance of BPH to triflumezopyrim, nitenpyram, and dinotefuran increased rapidly. The average resistance ratio of BPH to triflumezopyrim increased from 2.5 to 7.1 fold, nitenpyram from 18.3 to 37.7 fold, and dinotefuran from 119.5 to 268.1 fold. All populations remained extremely high resistance to imidacloprid, thiamethoxam, and buprofezin. Most field populations of BPH maintained moderate resistance to chlorpyrifos and sulfoxaflor, and high resistance to pymetrozine by rice stem dipping method. However, considering the reproduction-inhibiting character of pymetrozine, susceptible to low resistance levels to pymetrozine were monitored by Insecticide Resistance Action Committee (IRAC) NO.005 method. This result indicated that pymetrozine might lose efficacy in the control of application generation, but it could significantly inhibit the reproduction of field populations of BPH. Additionally, we compared the expression levels of 11 nicotinic acetylcholine receptor (nAChR) genes, the targets of nAChR competitive modulators, in four field populations (FY23, YH23, LJ23, LP23) and susceptible strain. The expression level of nAChR α4 was significantly reduced in all field populations, while α1, α2, α6, and α7 were significantly reduced in some field populations. Our findings provide valuable information for resistance management strategies in N. lugens and offer new insights into the resistance mechanisms of nAChR competitive modulators.

ANTIBACTERIAL THERAPY IN SEPSIS PATIENTS

Today, sepsis, the cause of which is purulent-inflammatory processes of soft tissues, accounts for more than 45% of cases. In most multidisciplinary hospitals, the frequency of gram-positive and gram-negative sepsis is approximately the same. Antibacterial therapy (ABT) is the most important component of the complex therapy of sepsis, and early adequate empiric ABT leads to a decrease in mortality and the frequency of complications. ABT of sepsis at the beginning of treatment, in most cases, is empirical in nature, but it should be remembered that taking the material for microbiological research must be done before the start of antibacterial therapy! According to the principles adopted in the guideline "Sepsis - 3", the use of antibiotics for the treatment of sepsis is a necessary component, the effectiveness of which cannot be doubted. It should be remembered that a delay in the appointment of an antibacterial drug to patients with sepsis and septic shock for 1 hour leads to an increase in the risk of death of the patient by 7,6%. Empiric ABT should be initiated with a broad-spectrum regimen of one or more antibiotics in patients with sepsis or septic shock to cover all possible pathogens (including bacterial, possibly fungal, or viral). Empiric ABT should be narrowed after identification of the pathogen and determination of its sensitivity and/or when adequate clinical improvement is registered. There are no indications for long-term systemic antibacterial prophylaxis in patients with severe forms of inflammatory conditions of non-infectious origin (for example, severe pancreatitis, burns). Measurement of procalcitonin levels can be used to shorten the duration of antibacterial therapy in patients with sepsis. Rapid interpretation of the severity of the infectious process can be performed using ACCP/SCCM sepsis diagnostic criteria, organ dysfunction criteria (gSOFA, SOFA, MODS) or rapid procalcitonin test. Microbiological diagnosis of sepsis is the main factor in prescribing adequate ABT regimens. In the case when the same microorganism is released from the probable source of infection and from the peripheral blood, its etiological role in the development of sepsis should be considered as evidential. The standard for testing blood for sterility is the collection of material from two peripheral veins with an interval of up to 30 minutes, while blood from each vein must be collected in two vials. It is not permissible to take blood from the catheter! Building an ABT algorithm taking into account the etiology and characteristics of resistance of microorganisms to antibacterial drugs is the most optimal approach. Тoday, the optimal regimen of empiric ABT of sepsis with PON is carbapenems - as drugs that have the widest spectrum of action and to which the lowest level of resistance is observed among intra-hospital strains of gram(-) bacteria. In some cases, an alternative to carbapenems is cefepime, ceftaroline, protected by antipseudomonas β-lactams (cefaperazone/sulbactam, piperacillin/tazobactam) and "respiratory" fluoroquinolones. In cases of ineffectiveness of the indicated regimens of ABT, the feasibility of additional appointment of glycopeptides (vancomycin, teicoplanin or linezolid), as well as systemic antimycotics (fluconazole) should be evaluated. The latter should also be prescribed after 7-10 days after the start of ABT in a prophylactic dose of 150 mg per week.

Discovery and synthesis of leaderless bacteriocins from the Actinomycetota.

Leaderless bacteriocins are a unique class of bacteriocins that possess antimicrobial activity after translation and have few cases of documented resistance. Aureocin A53 and lacticin Q are considered two of the most well-studied leaderless bacteriocins. Here, we used in silico genome mining to search for novel aureocin A53-like leaderless bacteriocins in GenBank and MGnify. We identified 757 core peptides across 430 genomes with 75 species found currently without characterized leaderless bacteriocin production. These include putative novel species containing bacteriocin gene clusters (BGCs) from the genera Streptomyces (sp. NBC_00237) and Agrococcus (sp. SL85). To date, all characterized leaderless bacteriocins have been found within the phylum Bacillota, but this study identified 97 core peptides within the phylum Actinomycetota. Members of this phylum are traditionally associated with the production of antibiotics, such is the case with the genus Streptomyces. Actinomycetota is an underexplored phylum in terms of bacteriocin production with no characterized leaderless bacteriocin production to date. The two novel leaderless bacteriocins arcanocin and arachnicin from Actinomycetota members Arcanobacterium sp. and Arachnia sp., respectively, were chemically synthesized and antimicrobial activity was verified. These peptides were encoded in human gut (PRJNA485056) and oral (PRJEB43277) microbiomes, respectively. This research highlights the biosynthetic potential of Actinomycetota in terms of leaderless bacteriocin production and describes the first antimicrobial peptides encoded in the genera Arcanobacterium and Arachnia.IMPORTANCEBacteriocins are gathering attention as alternatives to current antibiotics given the increasing incidence of antimicrobial resistance. Leaderless bacteriocins are considered a commercially attractive subclass of bacteriocins due to the ability to synthesize active peptide and low levels of documented resistance. Therefore, in this work, we mined publicly available data to determine how widespread and diverse leaderless bacteriocins are within the domain of bacteria. Actinomycetota, known for its antibiotic producers but lacking described and characterized bacteriocins, proved to be a rich source of leaderless bacteriocins-97 in total. Two such peptides, arcanocin and arachnicin, were chemically synthesized and have antimicrobial activity. These bacteriocins may provide a novel source of novel antimicrobials that could aid in the development of future alternative antimicrobials and highlight that the Actinomycetota are an underexplored resource of bacteriocin peptides.

Investigation of resistance ratios and resistance mechanisms of Cydia pomonella (L.) (lepidoptera: Tortricidae) populations collected from apple orchards in Isparta (Türkiye) against some insecticides

The codling moth, Cydia pomonella is an important pest that causes significant economic losses in apples and walnuts in the world. The aim of this study was to investigate, for the first time in Türkiye, the resistance status and resistance mechanisms of codling moth, Cydia pomonella against indoxacarb, deltamethrin and emamectin benzoate. All apple orchard populations developed resistance ratios ranging from 3.38 to 22.37-fold to deltamethrin, 5.67–29.87-fold to indoxacarb and 1.46–3.05-fold to emamectin benzoate. The interaction of some synergists triphenyl phosphate (TPP), piperonyl butoxide (PBO) and diethyl maleate (DEM) with indoxacarb and deltamethrin was analyzed in the susceptible, MAREM and Tepeli populations with moderate resistance to indoxacarb and deltamethrin. While indoxacarb + TPP showed a significant synergistic effect only in MAREM population, a significant synergistic effect was observed with indoxacarb + TPP and indoxacarb + PBO in Tepeli population. The activities of detoxifying enzymes [esterase, glutathion –S– transferase (GST) and cytochrome P450 monooxygenase (P450)] studied by biochemical methods showed some variation depending on the population. The results of biochemical analyses showed that esterase and GST enzyme activities of all populations was between 0.51 and 0.94, 0.77 and1.29 mOD min−1mg−1 proteins, respectively. The P450 enzyme activities ranged from 0.53 to 0.78, RFU min−1mg−1 proteins. In addition, the L1014F knockdown mutation (CTT to TTT) corresponding to leucine to phenylalanine amino acid substitution of the voltage-gated sodium channel in Cydia pomonella was determined in MAREM and Tepeli populations. It was determined that while MAREM and Tepeli populations developed moderate resistance, the other populations developed a low level resistance to deltamethrin and indoxacarb. On the other hand, all populations developed a low level resistance to emamectin benzoate. The P450 and esterase enzyme activities were significantly higher in MAREM and Tepeli populations which were resistant to deltamethrin and indoxacarb than the susceptible population. In addition, a Kdr point mutation L1014F was detected in the deltamethrin resistant MAREM and Tepeli populations.