Low-level Resistance Research Articles

The validity and reliability of a hydraulic resistance device for assessing resisted sprint time.

The aim of this study was to assess the validity and reliability of a hydraulic resistance device (HRD) for monitoring sprint split times under different loads within and between sessions. Three 20-m sprints with low (15 N), medium-low (40 N), medium-high (50 N), and high (130 N) HRD resistance levels (loads) were performed on two separate occasions 14 days apart. Twenty-four student athletes (24.8 ± 3.8 years) participated in the first session and 13 (24.1 ± 3.2 years) of them in the second session. Resisted sprints split times over a distance of 0-20 m (t0-5, t0-10, t0-20, t5-10, t10-15, t15-20) were measured simultaneously with magnetic incremental encoder embedded in the HRD and a system of single-beam timing gates. The results showed acceptable to high within session (ICC3,1 = 0.91-0.99; CV = 0.92%-3.38%) and between session (ICC3,1 = 0.82-0.99; CV = 1.62%-4.84%) reliability of HRD for measuring all split times at all loads. The minimal detectable change between sessions ranged from 3.3% at high load to 9.9% at low load. The HRD systematically underestimated timing gates times at all loads (bias = 2.01-11.08%), yet good to excellent consistency was observed between the HRD and timing gates, specifically for t0-10 and t0-20 (ICC3,k lower 95% CI = 0.84-0.99). Due to high reliability and good validity in monitoring resisted sprint times, the HRD holds potential for practical and research applications.

Summer mortality syndrome bacterial pathogens in farmed Nile tilapia (Oreochromis niloticus).

The high summer mortality in many fish farms, which had detrimental economic and social implications, was a serious challenge that the fish industry had to deal with. With an examination of the most effective antibiotic, the ongoing research was intended to shed light on the identification of the main bacterial pathogens associated with the summer mortality syndrome in the diseased farmed Nile tilapia. Six hundred dead Nile tilapia samples that had suffered from summer mortality were collected from several fish farms between May and October of 2022. The gathered fish displayed hemorrhagic areas on the skin, scale detachment, fin degeneration, erosions, skin ulcers, and corneal opacity with unilateral and/or bilateral exophthalmia. The most prominent internal appearance was swelling of the internal organs with sanguineous ascetic fluid. There were 225 bacterial isolates found. Six species were identified through phenotypic and biochemical analysis; they were Aeromonas, Vibrio, Streptococcus, Pseudomonas, Enterococcus, and Edwardsiella spp., in descending percentage, respectively. Aeromonas spp., Vibrio spp., and Streptococcus spp. were the three most frequent isolated bacterial pathogens. The identification of Aeromonas hydrophila, Vibrio spp., and Streptococcus iniae, the three most common bacterial isolates, was confirmed by molecular analysis by polymerase chain reaction. Most of the tested strains were found to be responsive to Ciprofloxacin (CIP), Gentamicin (CN), and Chloramphenicol (C) but resistant to Amoxicillin (AMX), according to an antibiotic sensitivity test. The three most dangerous common bacterial infections discovered during mass-farmed tilapia summer mortality are A. hydrophil a, Vibrio sp., and S. iniae. This makes it clear that high water temperatures may raise the possibility of bacterial infections, which could cause widespread tilapia mortality and substantial financial losses. Therefore, it is crucial to maintain a beneficial fish culture, environment, and husbandry practices to enhance the tilapia-rearing environment and lessen the virulence of the disease. Isolated bacterial strains showed low levels of resistance to AMX but were vulnerable to CIP, CN, and C.

A new amino acid substitution in the MvALS1 gene of metsulfuron-methyl resistant biotypes Monochoria vaginalis (Burm. f.) C. Presl from West Java, Indonesia.

The most bothersome weed in rice fields in the Indonesian province of West Java is Monochoria vaginalis (Burm. F.) C. Presl, an aquatic herbaceous plant. Metsulfuron-methyl has long been used in wetland rice in West Java with a high enough intensity. However, the case of Monochoria vaginalis resistance to metsulfuron-methyl herbicides in Indonesia has not been widely reported and investigated. The study aims to (1) classify the resistance level of M. vaginalis toward metsulfuron-methyl, (2) identify Target Site Resistance (TSR) mechanism mutations in the MvALS1 gene of the resistant biotype of M. vaginalis. The Whole Plant Pot Test method was utilized to assess the resistance level of Monochoria vaginalis. Following that, all samples were subjected to DNA sequencing using the PCR method to identify mutations in the MvALS1 gene from the resistant biotype. After then, this study used DUET, a server with an integrated computational methodology, to anticipate the effect of mutations on protein stability. The result showed that Monochoria vaginalis from Rawamerta, Karawang showed a moderate level of resistance to metsulfuron-methyl with a resistance ratio of 6.00, Patokbeusi, Subang showed a low level of resistance to metsulfuron-methyl with a resistance ratio of 3.89, compared to susceptible Monochoria vaginalis. Nucleotide base alignment in the MvALS1 gene revealed that base substitutions occurred in the Monochoria vaginalis biotype from Rawamerta and Patokbeusi, resulting in 5 amino acid substitutions: Ser-64-Ala, Asp-66-Glu, Asn-240-Asp, Glu-426-Asn, and Ser-469-Asn and Sukra: Ser-64-Ala, Asp-66-Glu, and Asn-240-Asp. The analysis showed that S64A, D66E, and N240D stabilize the protein, whereas E426N and S469N destabilize it. This study confirms for the first time that Ser-64-Ala, Asn-240-Asp, and Glu-426-Asn amino acid mutations were found in cases of M. vaginalis resistance to metsulfuron-methyl (ALS inhibitor).

Dual bombard by Cytomegalovirus and Mycobacterium tuberculosis in a renal transplantee

Abstract In the first year following an organ transplant, more than 80% of patients encounter a minimum of one occurrence of infection. Here, we report a case of coinfection of the Cytomegalovirus (CMV) and Mycobacterium tuberculosis (MTB) in a kidney transplantee. Computed tomography chest (CT chest) showed bilateral ground-glass opacities. By Cytomegalovirus DNA polymerase chain reaction, 9360 copies were detected in plasma. Cartridge-based nucleic acid amplification test from bronchial washings tested positive for MTB with very low-level resistance to rifampicin. He was started on category-I antitubercular therapy without rifampicin and intravenous valganciclovir. The clinical status of the patient improved after 1 month of treatment.

The first vanE-type vancomycin resistant Enterococcus faecalis isolates in Norway – phenotypic and molecular characteristics

We aimed to characterize the vanE cluster and its genetic support in the first Norwegian vanE-type isolates and assess genetic relatedness to other vanE isolates. Two vanE-type vancomycin resistant Enterococcus faecalis (vanE-VREfs) isolates (E1 and E2) recovered from the same patient 30 months apart were examined for antimicrobial susceptibility, genome sequence, vancomycin resistance induction, vanE transferability, genome mutation rate, and phylogenetic relationship to E. faecalis closed genomes and two vanE-VREfs from North America. The ST34 E1 and E2 strains expressed low-level vancomycin resistance and susceptibility to teicoplanin. Their vanE gene clusters were part of a non-transferable Tn6202. The histidine kinase part of vanSE was expressed although a premature stop codon (E1) and insertion of a transposase (E2) truncated their vanSE gene. The vancomycin resistance phenotype in E1 was inducible while constitutive in E2. E1 showed a 125-fold higher mutation rate than E2. Variant calling showed 60 variants but nearly identical chromosomal gene content and synteny between the isolates. Their genomes also showed high similarity to another ST34 vanE-VREfs from Canada. In-depth genomic analyses of the first two vanE-VREfs found in Europe identified a single chromosomal insertion site of two variants of vanE-conferring Tn6202. Single nucleotide polymorphism (SNP) and core genome multilocus sequence type (cgMLST) analyses show the genomes are different. This can be explained by the high mutation rate of E1 and acquisition of different mobile genetic elements; thus, we believe the two isolates from the same patient are genetically related. Genome similarities also suggest relatedness between the Canadian and Norwegian vanE-VREfs.

Features of the Application of the Method of Socio-Psychological Training in the Formation of Students' Stress Resistance

The paper deals with such concepts as «social-psychological training» and «stress resistance»; the features of the application of this method in the formation of students' stress resistance are studied.One of the primary tasks of modern society in working with youth is the formation of a high level of sociopsychological adaptation. Currently, an active search and development of new forms and methods of both individual and group work with students is underway. In the diverse arsenal of methodological tools, a special place is given to socio-psychological training.The purpose of this psychological study was to study the features of the use of socio-psychological training as a means of forming students' stress resistance. During the primary diagnosis, two groups of students (control and experimental) were identified with a low level of stress resistance and a high level of stress.As part of the formative experiment, we developed and implemented a program of psychological support for students. Classes were held in the experimental group once a week for two months. After the formative experiment, the control stage of the study was carried out. At the control stage, the changes in the level of stress and stress tolerance of those who took (experimental group) and those who did not take part (control group) in the program were compared, thus, the effectiveness of the program of psychological support of students developed by us was tested. For re-diagnosis, the same methods were used as in the primary diagnosis at the ascertaining stage of the study.The methodological basis of the work was the theoretical provisions on the development of the group in the process of joint activity (L.G. Pochebut, G.M. Andreeva, E.S. Kuzmin, R.S. Nemov, etc.); ideas about the sociopsychological characteristics of the group (M.I. Bobneva, V.S. Ageev, P.K. Anokhin, etc.); conceptual foundations of personality development in the course of a specially organized psychological impact (A. Bandura, S.I. Makshanov, K. Levin, etc.); understanding and implementation of the methodology and methodology of socio-psychological training (L.A. Petrovskaya, Yu.N. Emelyanov, S.I. Makshanov).The research methods were theoretical analysis of scientific research; organizational methods; empirical methods: observation, psychodiagnostic methods, methods of statistical data processing.Comparative analysis of changes in the experimental and control groups (increase in stress resistance, reduction of stress and tension levels according to the corresponding coping strategies) allowed us to draw conclusions about the potential of applying the method of socio-psychological training in the formation of students' stress resistance.

Surveillance of antimicrobial resistance in Escherichia coli, Salmonella, and Campylobacter recovered from laying hens, their environment and products in Canada indicated a stable level of resistance to critically important antimicrobials, in varying time periods between 2007 and 2021

The study objective was to determine the occurrence and antimicrobial resistance (AMR) attributes of select foodborne bacteria recovered from egg-producing (layer) chickens between 2007 and 2021 using different sample matrices (Study 1: liquid whole eggs, Study 2: spent hen cecal samples, Study 3: environmental sponge swabs and fecal samples from layer chicken barns, and Study 4: fecal samples from layer chicken barns). Samples from each study were submitted for the culture of Escherichia coli and Salmonella. In addition, samples from layer chicken barns were submitted for the culture of Campylobacter. Isolates were tested by microbroth dilution and interpreted using both clinical breakpoints and epidemiological cut-offs (ECOFFs). The ECOFFs were applied to detect non-wild type (NWT) strains. The proportion of resistant, NWT, and distribution of minimum inhibitory concentrations (MIC) were assessed. Ceftriaxone resistance was detected at a low-level in E. coli (< 2 %, all studies) and Salmonella (4.3 %, Study 2). Very low-level ciprofloxacin resistance was detected in E. coli (<1 %, Study 1) but a slightly elevated ciprofloxacin NWT E. coli (1 % to 6 %) observed. Only the farm fecal samples in Studies 2 and 3 were tested for Campylobacter as part of its study design, and moderate level ciprofloxacin resistance (<15 %) was observed. The MIC distribution patterns were similar across the organisms tested/studies and no substantial shifts in the distributions were detected. This analysis demonstrated that resistance to very important antimicrobials in bacteria from layers in Canada remains low, however, the detection of ciprofloxacin-resistant Campylobacter and the implications of this observation to the safety of egg products, and the role of laying flocks (i.e., as reservoir for resistant organisms) needs to be investigated.

Field-testing whitebark pine resistance to white pine blister rust: A simple, effective approach to progeny testing for restoration

The endangered conifer whitebark pine (Pinus albicaulis), native to high elevation forests of western North America, is declining mainly due to the introduced pathogen Cronartium ribicola, causing the disease white pine blister rust. Low levels of genetic resistance to blister rust are present in whitebark pine populations. Traditional methods of inoculating seedlings to determine resistance to the rust are costly, labour intensive, and have limited capacity due to facilities. This presents a bottleneck in the development of resistant material for restoring stands that have been heavily infected by the rust. Here we test an alternative approach to controlled inoculations that could screen large numbers of families with lower costs and requiring fewer specialized resources. We screened 214 open-pollinated families from 44 provenances from British Columbia (BC), Washington (WA), Oregon (OR), Idaho (ID), Montana (MT), and Nevada (NV) to determine: (1) the effectiveness of natural rust inoculation from Ribes nigrum in a common garden; (2) family- and provenance-level resistance to blister rust; and (3) climate variables related to population-level rust resistance. Eighty-one of these families were previously screened by the US Forest Service in Cottage Grove, Oregon using standard artificial inoculation methods. The natural inoculation was effective, with 73 % of seedlings displaying stem symptoms of the disease, and 95 % showing rust infection. A clear relationship was found between distance from the nearest Ribes nigrum plant and severity of blister rust. Linear mixed models with spatial correlations were fitted to rust infection data using ASReml-R to estimate breeding values, heritability, and among-population differentiation (QST) for rust resistance. Population differentiation for rust resistance was moderate, with the highest resistance in provenances from the Cascade Mountains of Washington, and the most susceptible families from the BC Chilcotin and Okanagan regions. Heritability of rust resistance was moderate (0.23). The field testing was broadly consistent with classifications of families into resistant, moderate, and susceptible groups based on artificial inoculations. This method of screening could be used at a broader scale to determine families resistant to white pine blister rust without specialized testing facilities and increase the availability of resistant seedlings for restoration.

The phenomenon of stress resistance as a leading factor in preserving the health of schoolchildren

The authors of the article emphasize that today the study of the phenomenon of stress resistance is becoming interdisciplinary, and stress and stress resistance are the subject of research by scientists from various fields: physicians, psychologists, educators, biologists, sociologists, etc. The purpose of the study is to carry out a theoretical content analysis of the phenomenon of stress resistance as a factor in maintaining schoolchildren's health. It is indicated that modern scientists are actively studying the phenomenon of stress resistance and there are a number of definitions of the concept of “stress resistance”. It is noted that stress resistance is a process and result of successful adaptation to difficult or challenging life circumstances, especially through mental, emotional and behavioral flexibility and adaptation to external and internal requirements. This quality of students' personality is influenced by various factors: cognitive, personality and innate, as well as environment and experience. The factors influencing the stress resistance of students are investigated; the main characteristics of personality stress resistance are summarized.&#x0D; Conclusions: The phenomenon of stress resistance is attracting the attention of modern researchers in Ukraine and the world. Stress tolerance is a set of personal qualities that allow one to endure stressful situations or mitigate their consequences. A low level of stress resistance reduces the physical and mental health of children and youth. Therefore, it is an urgent task to teach stress resistance to pupils of different school ages and students in the educational process of physical education.

Genomic insights into Enterococcus faecium isolates from marine bivalves highlight One Health concerns and healthcare linkages.

Enterococci, especially Enterococcus faecium, are one of today's leading causes of multidrug-resistant infections in hospital settings. The marine environment may harbour enterococci, but its role as an evolutionary niche and as a vector for the spread of enterococci is sparsely investigated. Hence, by applying enterococci in bivalves as a sentinel tool, this study aimed to describe the prevalence of enterocooci along the Norwegian coast and in addition the phylogeny of E. faecium in particular. Enterococci in batch samples of marine bivalves, harvested from 86 different locations, were quantitatively examined by a culture-dependent most probable number (MPN) method. Isolates were identified by MALDI-TOF-MS prior to antimicrobial susceptibility testing by broth microdilution. In-detail analyses of a representative selection of E. faecium isolates (n=148) were done by Illumina whole-genome sequencing, and assembled genomes were compared to closed E. faecium genomes in the public databases and to genomes from commensal and clinical isolates from Norway. Diversity among E. faecium within the same batch sample of bivalves was also explored. Enterococci were detected in 287 of the 471 examined bivalve samples, but in low concentrations with a median value of <18 MPN /100 g. From positive samples, 479 isolates of enterococci were identified belonging to ten different species, where E. faecium (n=247), Enterococcus hirae (n=114) and Enterococcus faecalis (n=66) were most frequently found. Resistance towards one or more antimicrobial agents was observed in 197 isolates (41 %), none of the isolates showed acquired resistance to vancomycin or linezolid. Phylogenetic analyses revealed high diversity among the E. faecium isolates and showed that the marine niche is dominated by strains from the non-clinical setting belonging to clade A2 (n=85) and B (E. lactis) (n=60). Only three isolates belonged to the hospital-associated clade A1 (ST80 and ST117). Two of these clustered with one isolate from a hospitalized patient and one from a non-hospitalized person. This study demonstrated a high prevalence, but low concentrations of enterococci in bivalves, and low levels of antimicrobial resistance. E. faecium genomes showed high population diversity and that very few E. faecium isolates in bivalves may have arisen from the human healthcare system. A systematic surveillance of target micro-organisms applying methods examining multiple isolates from the same bivalve sample provides important data to assess the enterococcal phylogeny, antimicrobial resistance and the level of faecal pollution in the marine environment.

Methicillin resistant Staphylococcus aureus in the United Arab Emirates: a 12-year retrospective analysis of evolving trends.

Methicillin resistant Staphylococcus aureus (MRSA) is a major contributor to the global burden of antimicrobial resistance (AMR). As MRSA continues to evolve, the need for continued surveillance to evaluate trends remains crucial. This study was carried out to assess MRSA trends in the United Arab Emirates (UAE) based on analysis of data from the national AMR surveillance program. We carried out a 12-year (2010-2021) retrospective analysis of MRSA demographic and microbiological data collected as part of the UAE national AMR surveillance program. Participating centers from across the country routinely submit AMR surveillance data collected by trained personnel to the National AMR Surveillance Committee, where data is analyzed using a unified WHONET platform. Data on non-duplicate isolates associated with clinical infections were obtained and included in the analysis. A total of 29,414 non-duplicate MRSA isolates associated with clinical infections were reported between 2010 and 2021 (2010: n = 259; 2021: n = 4,996). MRSA represented 26.4% of all S. aureus (n = 111,623) isolates identified during the study period. In 2010, among the S. aureus isolates with reported oxacillin testing, 21.9% (n/N = 259/1,181) were identified as MRSA and this showed an increase to 33.5% (n/N = 4,996/14,925) in 2021. Although there was variation in the distribution of MRSA across the seven emirates of the country, most had an upward trend. Patient demographics reflected a male preponderance, with most being adults and from the outpatient setting. Isolates were mostly from skin and soft tissue infection specimens (72.5%; n/N = 21,335/29,414). Among the inpatients (N = 8,282), a total of 3,313 MRSA isolates were from specimens obtained ≤ 48 h after admission indicative of community acquired infection. Increasing resistance trends were observed for most antibiotics including ciprofloxacin, levofloxacin, moxifloxacin, erythromycin, gentamicin, trimethoprim-sulfamethoxazole, and quinupristin/dalfopristin. Low levels of resistance (0.0-0.8%) were sustained for linezolid except for 2015, 2016, and 2017 with 2.5, 2.6, and 2.9%, respectively. No confirmed vancomycin resistance was reported. The increasing trend of MRSA isolates associated with clinical infections in the hospital and community settings is a concern. Continued monitoring including incorporation of genomic surveillance and infection control measures are recommended to stem the dissemination.

Low Prevalence of Antimalarial Resistance Mutations in India During 2014-2015: Impact of Combining First-line Therapy With Primaquine.

Antimalarial drug resistance surveillance and containment are crucial for countries aiming to eliminate malaria. Monitoring resistance evolution through studies before and after treatment policy changes is essential. A total of 939 Plasmodium falciparum-positive blood samples were collected between 2014 and 2015 across 10 sites in India, categorized into 4 geographic clusters. Polymerase chain reaction-amplified products were sequenced to identify point mutations at drug resistance-conferring genes (Pfdhfr, Pfdhps, Pfmdr1, and Pfk13). Triple Pfdhfr mutants were found only in northeast India bordering Myanmar, while the wild type (WT) was dominant in central India. Pfdhps WTs were prevalent in all areas, and no double mutants were found. Except in northwest India, Pfmdr1 WT was dominant in all clusters. Nonsynonymous double mutations were only found in northwest India. Only synonymous mutations occurred in Pfk13. These were found in central India at a low frequency. The pattern of linkage disequilibrium and principal component analysis reflects low pressure for drug resistance and heterogeneity between the geographic clusters. Resistance levels were highest in northeast India, close to the Myanmar border, where resistance is common. Primaquine has been widely used as a gametocidal and schizonticidal drug, likely contributing to maintaining low drug resistance levels and preventing strong selection for resistance.

Antibiotic Guideline Adherence at the Emergency Department: A Descriptive Study from a Country with a Restrictive Antibiotic Policy.

Denmark has a low level of antimicrobial resistance (AMR). Patients hospitalized with suspected infection often present with unspecific symptoms. This challenges the physician between using narrow-spectrum antibiotics in accordance with guidelines or broad-spectrum antibiotics to compensate for diagnostic uncertainty. The aim of this study was to investigate adherence to a restrictive antibiotic guideline for the most common infection in emergency departments (EDs), namely community-acquired pneumonia (CAP). This multicenter descriptive cross-sectional study included adults admitted to Danish EDs with a suspected infection. Data were collected prospectively from medical records. We included 954 patients in the analysis. The most prescribed antibiotics were penicillin with beta-lactamase inhibitor at 4 h (307 (32.2%)), 48 h (289 (30.3%)), and day 5 after admission (218 (22.9%)). The empirical antibiotic treatment guidelines for CAP were followed for 126 (31.3%) of the CAP patients. At 4 h, antibiotics were administered intravenously to 244 (60.7%) of the CAP patients. At day 5, 218 (54.4%) received oral antibiotics. Adherence to CAP guidelines was poor. In a country with a restrictive antibiotic policy, infections are commonly treated with broad-spectrum antibiotics against recommendations.

The evolving story of sulfoxaflor resistance in the green peach aphid, Myzus persicae (Sulzer).

The green peach aphid, Myzus persicae (Sulzer), is one of the most economically important crop pests worldwide. Insecticide resistance in this pest was first detected over 60 years ago, with resistance in M. persicae now spanning over 80 active ingredients. Sulfoxaflor is a relatively new insecticide that is primarily used to control sap-feeding insects. In 2018 resistance to sulfoxaflor was discovered in field populations of M. persicae in Australia. This study aimed to determine the current distribution and phenotypic levels of sulfoxaflor resistance in Australian clones of M. persicae and to investigate how these patterns relate to clonal type. For the first time, we show there is low-level resistance (8-26-fold) distributed across Australia, with resistance being detected in aphids collected from approximately 20% of all M. persicae collected and screened. Furthermore, this study shows sulfoxaflor resistance is found in twoM. persicae haplotypes, providing evidence that there have been multiple independent evolutionary events which have given rise to sulfoxaflor resistance in this species. These findings have important implications for the chemical control of M. persicae in Australia, especially when considering the broader genetic background of these aphids which are known to harbour a number of other insecticide resistance mechanisms. We recommend continuous monitoring of sulfoxaflor resistance in field populations of M. persicae (in Australia and elsewhere) and further research into the underlying genetic mechanisms conferring resistance to sulfoxaflor in both clonal haplotypes. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Polymorphism of Drug Resistance Genes dhfr and dhps in Plasmodium falciparum Isolates among Chinese Migrant Workers Who Returned from Ghana in 2013.

In 2013, an epidemic of falciparum malaria involving over 820 persons unexpectedly broke out in Shanglin County, Guangxi Zhuang Autonomous Region, China, after a large number of migrant workers returned from Ghana, where they worked as gold miners. Herein, we selected 146 isolates randomly collected from these patients to investigate the resistance characteristics of the parasite to sulfadoxine-pyrimethamine (SP) by screening mutations in the dhfr and dhps genes. All 146 isolates were successfully genotyped for dhps, and only 137 samples were successfully genotyped for dhfr. In the dhfr gene, point mutations occurred at three codons: 51 (83.2%, 114/137), 59 (94.9%, 130/137), and 108 (96.4%, 132/137). In the dhps gene, mutations occurred at four codons: 436 (36.3%, 53/146 for S436A, 0.7%, 1/146 for S436Y), 437 (95.2%, 139/146), 540 (3.4%, 5/146), and 613 (2.7%, 4/146). All 146 isolates had mutations in at least one codon, either within dhfr or dhps. Quadruple mutation I51R59N108/G437 (41.1%, 60/146) of partial or low resistance level was the most prevalent haplotype combination. Quintuple I51R59N108/G437E540 accounted for 2.1% (3/146). Sextuple I51R59N108/A436G437S613 was also found and accounted for 1.4% (2/146). A chronological assay incorporating two sets of resistance data from the studies of Duah and Amenga-Etego provided an overview of the resistance trend from 2003 to 2018. During this period, the results we obtained generally coincided with the total development tendency of SP resistance. It can be concluded that Plasmodium falciparum samples collected from Chinese migrant workers from Ghana presented prevalent but relatively partial or low resistance to SP. A chronological assay incorporating two sets of data around 2013 indicates that our results possibly reflect the SP resistance level of Ghana in 2013 and that the possibility of increased resistance exists. Therefore, reasonable drug use and management should be strengthened while also maintaining a continuous screening of resistance to SP. These findings also underscore the need to strengthen the prevention of malaria importation from overseas and focus on preventing its reintroduction and transmission in China.

Prevalence of antimicrobial-resistant Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis

Introduction. Violation of sputum evacuation in patients with cystic fibrosis leads to the persistence of microorganisms. Most often, the microorganisms are isolated from sputum in patients with cystic fibrosis: Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia complex, etc. For the treatment of infections caused by P. aeruginosa, the following groups of antibiotics are used: aminoglycosides, carbapenems, polymyxins, cephalosporins, fluoroquinolones, inhibitor-protected penicillins and fosfomycin.Aim. To the study is to determine antimicrobial resistance in P. aeruginosa isolated from patients with cystic fibrosis.Materials and methods. An analysis of 87 results of sputum, biomaterial from the posterior wall of the pharynx and nose was made.Results and discussion. Biomaterial was taken from the nasal in 4.6% cases, from the posterior pharyngeal wall in 35.6% and sputum in 59.8%. The lowest level of resistance was registered in strains isolated from the nasal cavity. Microorganisms isolated from the posterior pharyngeal wall showed a higher level of antibiotic resistance. The sensitivity data of sputum isolates were similar to the results from the posterior pharyngeal wall. The highest level of resistance was obtained to aminoglycosides (19.3%) and carbapenems (14.8%). In addition, 12.5% of P. aeruginosa isolates were resistant to sodium colistimethate, 10.2% to fluoroquinolones. The lowest level of insensitivity was found to cephalosporins (5.7%) and protected beta-lactams (4.5%). The revealed trend of decreasing sensitivity, in our opinion, is associated with a greater frequency of antibiotic use.Conclusion. Chronic P. aeruginosa infection in patients with CF contributes to a more severe course of the disease and increases the risk of complications.

Comparative genotypic characterization related to antibiotic resistance phenotypes of clinical carbapenem-resistant Acinetobacter baumannii MTC1106 (ST2) and MTC0619 (ST25)

BackgroundThe prevalence of Acinetobacter baumannii in nosocomial infections and its remarkable ability to develop antimicrobial resistance have been a critical issue in hospital settings. Here, we examined the genomic features related to resistance phenotype displayed by carbapenem-resistant A. baumannii (CRAB) MTC1106 (ST2) and MTC0619 (ST25).ResultsResistome analysis of both strains revealed that MTC1106 possessed higher numbers of antimicrobial resistance genes compared to MTC0619. Some of those genetic determinants were present in accordance with the susceptibility profile of the isolates. The predicted ISAba1 region upstream of blaOXA-23 gene was related to carbapenem resistance since this IS element was well-characterized to mediate overexpression of carbapenemase genes and eventually provided capability to confer resistance. Unlike MTC0619 strain, which only carried class B and D β-lactamase genes, MTC1106 strain also possessed blaTEM-1D, a class A β-lactamase. Regarding to aminoglycosides resistance, MTC0619 contained 5 related genes in which all of them belonged to three groups of aminoglycosides modifying enzyme (AME), namely, N-acetyltransferase (AAC), O-nucleotidyltransferase (ANT), and O-phosphotransferase (APH). On the other hand, MTC1106 lacked only the AAC of which found in MTC0619, yet it also carried an armA gene encoding for 16S rRNA methyltransferase. Two macrolides resistance genes, mph(E) and msr(E), were identified next to the armA gene of MTC1106 isolate in which they encoded for macrolide 2’-phosphotransferase and ABC-type efflux pump, respectively. Besides acquired resistance genes, some chromosomal genes and SNPs associated with resistance to fluoroquinolones (i.e. gyrA and parC) and colistin (i.e. pmrCAB, eptA, and emrAB) were observed. However, gene expression analysis suggested that the genetic determinants significantly contributing to low-level colistin resistance remained unclear. In addition, similar number of efflux pumps genes were identified in both lineages with only the absence of adeC, a part of adeABC RND-type multidrug efflux pump in MTC0619 strain.ConclusionsWe found that MTC1106 strain harbored more antimicrobial resistance genes and showed higher resistance to antibiotics than MTC0619 strain. Regarding genomic characterization, this study was likely the first genome comparative analysis of CARB that specifically included isolates belonging to ST2 and ST25 which were widely spread in Thailand. Taken altogether, this study suggests the importance to monitor the resistance status of circulating A. baumannii clones and identify genes that may contribute to shifting the resistance trend among isolates.

ALS gene overexpression and enhanced metabolism conferring Digitaria sanguinalis resistance to nicosulfuron in China.

Crabgrass (Digitaria sanguinalis) is a common malignant weed in corn fields in China. Recently, the acetolactate synthase (ALS) inhibitor, nicosulfuron, has shown decreasing efficacy against crabgrass. In order to elucidate the molecular basis of resistance to nicosulfuron in crabgrass, we conducted bioassays, combined with gene sequence analysis, relative expression and relative copy number analysis, to characterize resistance in crabgrass populations collected from Beijing, Heilongjiang, Jilin and Anhui provinces. Whole-plant dose-response results indicated that only population collected in Heilongjiang province (HLJ) had developed low level of resistance to nicosulfuron compared with the sensitive population (SD22). No known resistant mutation of ALS gene was found in HLJ population. The real-time fluorescence quantitative PCR results showed that the ALS gene copy number did not differ significantly between the HLJ and SD22 populations. However, the ALS gene expression in the HLJ was 2.07-fold higher than that of the SD22 population at 24 h after treatment with nicosulfuron. Pretreatment with the cytochrome P450 (CYP450) inhibitor malathion, piperonyl butoxide (PBO), and the glutathione S-transferase (GST) inhibitor 4-Chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) all partially reversed HLJ resistance. Among them, the synergistic effect of PBO and nicosulfuron is the most significant. This is the first report of resistance to nicosulfuron in crabgrass through ALS gene overexpression and possible metabolic resistance.

Antimicrobial susceptibilities and genomic characteristics of methicillin-resistant Staphylococcus aureus resistant to mupirocin in Stockholm, Sweden.

The aim of this study was to investigate antimicrobial susceptibilities and genomic characteristics of mupirocin-resistant MRSA isolates in Stockholm, Sweden. In total, 44 non-duplicate mupirocin-resistant MRSA isolates detected in Stockholm during 2010-2022 were investigated. Antimicrobial susceptibility testing was performed using broth microdilution method and further tested for high-level mupirocin-resistance (MuH) and rifampicin by Etest®. All isolates were subjected to whole genome sequencing. 41 isolates presented MuH with MICs ≥1024 mg/L whilst three isolates displayed low-level mupirocin resistance (MuL). mupA-gene was detected in all MuH isolates. Point mutations in ileS gene leading to N213D and V588F were identified in the three MuL isolates. Mutation in rpoB (H481N) was detected in a rifampicin-resistant isolate. Among the isolates, 15 multi-locus sequence types (MLST) were identified, with the four most common sequence types (ST22, ST72, ST8, and ST125) accounting for 66% of the isolates. Mupirocin-resistant MRSA in Stockholm was uncommon, with a percentage of <0.5% among MRSA cases during 2010-2022. In the present study, most mupirocin-resistant isolates were MuH and mupA-positive, predominantly linked to ST22 or ST72 isolates. MuL-resistance was associated with a point mutation in the IleS protein. A multidrug-resistant ST1-MRSA-IV strain was resistant to both mupirocin and rifampicin.

MOLECULAR IDENTIFICATION AND ANTIBIOGRAM OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS FROM WOUNDS OF BOTH IN- AND OUT-PATIENTS AT UNIVERSITY OF BENIN TEACHING HOSPITAL (UBTH), BENIN CITY, NIGERIA

Methicillin-resistant Staphylococcus aureus (MRSA) stands as a prominent bacterial pathogen associated with various human infections, characterized by its remarkable ability to rapidly develop resistance to multiple antibiotics. The study aimed to characterize MRSA isolated from wounds among hospital patients. A total of eighty-seven unique S. aureus isolates were obtained from wound cultures collected from patients at the University of Benin Teaching Hospital (UBTH) in Benin City, Nigeria. These samples underwent assessment for methicillin resistance through conventional cultural methods, and detection of methicillin resistance (mecA) and S. aureus specific (nuc) genes using PCR amplification. The MRSA isolates underwent assessment for antimicrobial resistance through disc diffusion testing and for virulence factors using phenotypic testing procedures. An overall prevalence of 34/87 (39.1%) MRSA isolates was recorded. Based on the source of the isolate, the distribution of MRSA isolates from in-patients was 22/56 (39.3%) and out-patients was 12/31 (39.7%). Total Panton valentine leucocidin (PVL) screening revealed 11/34 (32.4%). All the isolates were resistant to penicillin 34/34 (100%) and cefepime 34/34 (100%). Lower level of resistance was demonstrated towards ciprofloxacin 3/34 (8.8%). Overall, every isolate displayed resistance to at least three antibiotics, resulting in a multiple antimicrobial resistance index of at least 0.33. The total virulence factors observed were beta-hemolytic activity 22/34 (64.7%), protease activity 14/34 (41.2%), and lipase activity 19/34 (55.9%). This study emphasized the significance of regularly monitoring MRSA prevalence within both the hospital and the local community. Therefore, the need for better intervention and continuous enlightenment on risks associated with the abuse...