Resistance Monitoring Research Articles

The Pathogenicity Traits of Avian Pathogenic E. coli (APEC) O25-ST131 Associated with Avian Colibacillosis in Georgia Poultry and their Genotypic and Phenotypic Overlap with other ExPEC.

To characterize Escherichia coli O25 ST131 (O25-ST131) isolated from Georgia poultry, - a "global high-risk" clonal strain. Using multiplex PCR to detect target genes in 98 isolates of avian pathogenic E. coli (APEC) O25 recovered from avians diagnosed with colibacillosis (n=87) and healthy chicks (n=11) in Georgia, USA. Eighty-eight isolates were classified as sequence type (ST) ST131 clade b and 56% (n=49) belong to the phylogenetic group B2. Overall, 17% were identified as uropathogenic E. coli (UPEC) -like and 94% of the isolates formed strong to moderate biofilms. The extended-spectrum β-lactamases (ESBLs) encoding genes, blaCTX M-15 (24%), and carbapenemases encoding genes, blaOXA48 (16%) were also detected. The isolates harbored FIB (88%), FIC (28%), A/C (14%), and FIIA (6%) plasmid replicons. Interestingly, 78% of the isolates were found to be resistant to chicken serum and 92% showed capabilities for growth in human urine. The isolates showed phenotypic resistance to several antibiotics including chloramphenicol (63%), ciprofloxacin (57%), trimethoprim-sulfamethoxazole (28%), streptomycin (17%), cefoxitin and meropenem (14%) using the national antimicrobial resistance monitoring system (NARMS) panel. Overall, our study provides evidence of the virulence of these global "high-risk" clones in Georgia poultry with some isolates showing genotypic overlap between APEC and UPEC. Also, this clone harbored several virulence genes, antimicrobial-resistant genes (AMRs), and plasmids. Interestingly, the majority of APEC O25-ST131 isolates can survive and grow in both chicken serum and human urine and warrants further investigation of their potential pathogenicity for both chickens and humans.

Virulent and multidrug-resistant Aeromonas in aquatic environments of Kerala, India: potential risks to fish and humans.

Aeromonas inhabit diverse aquatic habitats and are recognized as both opportunistic and primary pathogens of fish and humans. This study delineates the biochemical and gyrB sequence-based molecular identification of 14 Aeromonas strains isolated from aquatic environments in Kerala, India, identifying them as A. dhakensis (50%), A. hydrophila (28.6%), and A. jandaei (21.4%). These strains exhibit a high prevalence of virulence genes (act, flaA, ser, gcat, lip, and ela) implicated in pathogenesis in both fish and humans. These findings underline the emergence of A. dhakensis, often misidentified as A. hydrophila, as a potential pathogen, highlighting the necessity for comprehensive identification methods. Significantly, all strains demonstrated beta-hemolysis and moderate to strong biofilm formation, enhancing their infectivity potential. Moreover, all isolates exhibited multidrug resistance, with a multiple antimicrobial resistance (MAR) index ranging from 0.39 to 0.56, and a significant presence of class 1 (500-1100bp) and class 2 (250-700bp) integrons, indicating their potential risk to both fish and human populations. Our results underscore the role of aquatic environment as a repository for virulent and multidrug-resistant Aeromonas spp., emphasizing the imperative for prudent antimicrobial usage and regular monitoring of antimicrobial resistance (AMR) in these environments.

Pathogenic Aspergillus spp. and Candida spp. in coastal waters from southern Brazil: an one health approach.

Aspergillus and Candida are ubiquitous fungi included in the group of high priority in the World Health Organization list of fungal pathogens. They are found in various ecosystems and the environmental role in increasing the resistance to antifungals has been shown. Thus, we aimed to determine the occurrence of Aspergillus spp. and Candida spp. pathogenic species in water samples from a coastal ecosystem from southern Brazil, and its antifungal susceptibility profile. Water samples were collected monthly at three environmental sites, over 25 months. Abiotic parameters of the water samples were analyzed as well as antifungal susceptibility. Aspergillus spp. and Candida spp. were detected in 44% (n = 33/75) and 40% (n = 30/75) respectively of the samples, totaling 67 and 96 isolates. Section Fumigati and C. parapsilosis were the most section/species isolated. Triazole resistance was detected in 3% of the Aspergillus spp. (2/67) and in 1% of the Candida spp. (1/96) isolates. Our study contributes with data showing that coastal aquatic environments can serve as a source of infection of resistant fungal isolates, proving the need for environmental surveillance and monitoring of fungal resistance in the One Health perspective.

Arising amitraz and pyrethroids resistance mutations in the ectoparasitic Varroa destructor mite in Canada

The ectoparasitic mite Varroa destructor remains a great threat for the beekeeping industry, for example contributing to excessive winter colony loss in Canada. For decades, beekeepers have sequentially used the registered synthetic varroacides tau-fluvalinate, coumaphos, amitraz, and flumethrin, leading to the risk of resistance evolution in the mites. In addition to the widespread resistance to coumaphos and pyrethroids, a decline in amitraz efficacy has recently been reported in numerous beekeeping regions in Canada. The goals of this study were to assess the evolution of resistance to amitraz in Canadian mite populations and to evaluate the presence and incidence of mutations previously associated with resistance to amitraz and pyrethroids in V. destructor. Our bioassay results confirmed the presence of amitraz-resistant mites in the population of Alberta. These phenotypic results were complemented by targeted genotyping of the octopamine receptor gene Octβ2R which revealed the presence of the mutation Y215H in 90% of tested apiaries with local allele frequencies ranging from 5 to 95%. The phenotypic resistance showed a significant correlation with the presence of this mutation across apiaries. In parallel, the L925I and L925M mutations in the voltage-gated sodium channel were identified in 100% of the tested apiaries with frequencies ranging from 33 to 97%, suggesting that resistance to pyrethroids remains widespread. These results support the notion that the practice of relying on a single treatment for a prolonged period can increase rates of resistance to current varroacides. Our findings suggest the need for large-scale resistance monitoring via genotyping to provide timely information to beekeepers and regulators. This will enable them to make an effective management plan, including rotation of available treatments to suppress or at least delay the evolution of resistance in V. destructor populations.

First detection of the S989P+V1016G+D1763Y haplotype and expansion of voltage-gated sodium channel mutations in Aedes aegypti in Taiwan in 2016-2023.

Aedes aegypti transmits various arthropod-borne diseases such as dengue, posing a significant burden to public health in tropical and subtropical regions. Pyrethroid-based control strategies are effective in managing this vector; however, the development of insecticide resistance has hindered these efforts. Hence, long-term monitoring of insecticide resistance in mosquito populations is crucial for effective vector and disease control. In this study, we identified insecticide resistance due to a voltage-gated sodium channel (vgsc) mutation in Ae. aegypti in Taiwan between 2016 and 2023. In total, 1,761 field-caught Ae. aegypti samples from Tainan, Kaohsiung, and Pingtung were genotyped. The frequencies of S989P, V1016G, T1520I, F1534C, and D1763Y amino acid variants increased over the surveillance period. A T1520I mutation was detected for the first time and has since rapidly spread throughout Taiwan. The triple-mutant haplotype PGTFY was first documented in Ae. aegypti. Moreover, the unmutated haplotype vanished in Taiwan, suggesting that the vgsc mutations were fixed in local populations of Ae. aegypti. Five resistance-associated genotypes, SVTCD/SVTCD, SGTFY/PGTFD, SVTCD/SGTFY, PGTFD/PGTFD, and SVTCD/PGTFD, exhibited an increased frequency and accounted for 76% of the total field population. We also detected the resistant genotype SVICD/PGTFD, and its frequency increased 13-fold in the field between 2016 and 2023. Moreover, we also observed that mutations differed geographically, with S989P mainly found in Kaohsiung and V1016G in Kaohsiung and Pingtung. The frequency of T1520I was noticeably higher in Kaohsiung, and D1763Y occurred mainly in Tainan. The emergence and expansion of mutations along with the disappearance of wild-type mosquitoes in Taiwan underscores the threat of resistance and difficulty of mosquito control in Taiwan as well as globally. This study determined the insecticide resistance status of Ae. aegypti in Taiwan, and the findings will be helpful for resistance monitoring in areas where pyrethroids are used to control Ae. aegypti.

Global phylogeography and antibiotic resistance characteristics of Morganella: An epidemiological, spatial, comparative genomic study.

Morganella morganii has been recognized as an important opportunistic pathogen that is becoming increasingly prevalent worldwide. However, the current global evolutionary dynamics and emergence of ARGs remain obscure. The present study determined the global distribution, genomic classification, phylogeny, and monitor longitudinal resistome changes. During 1900-2024, a total of 1027 non-duplicate Morganella genomes have been reported from 49 countries. The countries with the highest number were China (433), the USA (143), and France (74). Through ANI distance analysis and core genome phylogeny, Morganella was reclassified into six species: M. morganii, M. sibonii, M. chanii, M. laugraudii, M. kristinii, M. psychrotolerans. Further analysis using cgMLST identified 87 distinct genetic clusters and 737 singleton strains, indicating a high level of multi-locus sequence type diversity and local clonal outbreaks. Bayesian evolutionary analysis revealed the most recent common ancestor year and potential global transmission routes. A total of 195 ARGs were carried by Morganella isolates, with each genome containing between 2 and 544 ARGs. The most common ARGs were associated with resistance to the following drug-classes: aminoglycosides, beta-lactam, chloramphenicol, sulfamides, and tetracycline. Twenty-one carbapenemase-encoding genes were identified in 22 countries, with blaNDM-1, blaKPC-2, blaIMP-27, blaOXA-48, blaNDM-5, blaNDM-7, and blaVIM-1 being the most prevalent. Positive correlations were observed between ARGs and mobile genetic elements, like plasmids, ISs, and Tns, indicating frequent mobilization of certain ARGs by different mobile genetic elements (p < 0.05). In conclusion, Morganella isolates that are showing an upward trend in resistance and infection rates warrant a reclassification of their taxonomy and continuous monitoring for resistance.

Pyrethroid-resistant malaria vector Anopheles gambiae restored susceptibility after pre-exposure to piperonyl-butoxide: results from country-wide insecticide resistance monitoring in Tanzania, 2023

BackgroundEffective vector control interventions, notably insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are indispensable for malaria control in Tanzania and elsewhere. However, the emergence of widespread insecticide resistance threatens the efficacy of these interventions. Monitoring of insecticide resistance is, therefore, critical for the selection and assessment of the programmatic impact of insecticide-based interventions.MethodsThe study was conducted country-wide across 22 sentinel districts of Tanzania between May and July 2023 using standard World Health Organization susceptibility test with 1×, 5×, and 10× of deltamethrin, permethrin, and alpha-cypermethrin and discriminating concentrations of 0.25% pirimiphos-methyl. Synergist assays were conducted to explore the underlying mechanisms of the observed phenotypic pyrethroid-resistant mosquitoes. Three- to five-day-old wild adult females in the first filiar generation of Anopheles gambiae sensu lato (s.l.) were used for the susceptibility bioassays.ResultsAnopheles gambiae s.l. were resistant to all pyrethroids at the discriminating dose in most sentinel districts except in Rorya, which remains fully susceptible, and Ushetu, which remains susceptible to deltamethrin but not permethrin. In 5 sites (Bukombe, Ukerewe, Kilwa, Kibondo, and Kakonko), the An. gambiae s.l. species exhibited strong resistance to pyrethroids surviving the 10 X concentrations (mortality rate < 98%). However, they remained fully susceptible to pirimiphos-methyl in almost all the sites except in Kibondo and Shinyanga. Likewise, there was full restoration to susceptibility to pyrethroid following pre-exposure of An. gambiae s.l. to piperonyl-butoxide (PBO) in 13 out of 16 sites. The 3 sites that exhibited partial restoration include Kakonko, Tandahimba, and Newala.ConclusionThe evidence of widespread pyrethroid resistance of the major malaria vector justifies the decision made by the Tanzania National Malaria Control Programme to transition to PBO-based ITNs. Without this switch, the gains achieved in malaria control could be compromised. Equally important, the lack of full restoration to susceptibility observed in three sentinel districts upon pre-exposure to PBO merits close monitoring, as there could be other underlying resistance mechanisms besides oxidase metabolic resistance.

Tolerance mechanisms and molecular epidemiology of reduced susceptibility to chlorhexidine digluconate in different species of the Acinetobacter baumannii complex.

The objective of this study was to compare chlorhexidine digluconate and other antibiotics susceptibility of 4 species in Acinetobacter baumannii complex, and further investigate the CHG tolerance mechanisms and molecular epidemic characteristics. Of 889 A. baumannii complex isolates, A. baumannii, A. nosocomialis, A. pittii, and A. seifertii accounted for 84.2%, 10.9%, 3.4%, and 1.5%. A. baumannii was generally resistant to all tested antibiotics while other three species were commonly more susceptible. 92.1% (313/340) CHG-tolerant A. baumannii, 19.6% (19/97) CHG-tolerant A. nosocomialis, 3.3% (1/30) CHG-tolerant A. pittii and 15.4% (2/13) CHG-tolerant A. seifertii were identified. Furthermore, compared to A. baumannii ATCC 19606, upregulated expression was found in qacEΔ1, FabI and efflux pump encoding genes in CHG-tolerant A. baumannii, but the expression level of oprD was reduced. Additionally, only the expression level of FabI was increased in the CHG- tolerant A. nosocomialis, and the expression level of adeG was increased in the CHG- tolerant A. pittii and A. seifertii. Furthermore, CHG-tolerant A. baumannii may have a relatively high clonal correlation, the predominant ST of which was ST208 (90%, 36/40).It is rather necessary to identify specific species members among the A. baumannii complex for clinical treatment options and antibiotics resistance monitoring.

Unpacking WHO and CDC Bottle Bioassay Methods: A Comprehensive Literature Review and Protocol Analysis Revealing Key Outcome Predictors

Background Resistance monitoring is a key element in controlling vector-borne diseases. The World Health Organization (WHO) and Centres for Disease Control and Prevention (CDC) have each developed bottle bioassay methods for determining insecticide susceptibility in mosquito vectors which are used globally. Methods This study aimed to identify variations in bottle bioassay methodologies and assess the potential impact on the data that is generated. Our approach involved a systematic examination of existing literature and protocols from WHO and CDC, with a focus on the specifics of reported methodologies, variation between versions, and reported outcomes. Building on this, we experimentally evaluated the impact of several variables on bioassay results. Results Our literature review exposed a significant inconsistency in the how bioassay methods are reported, hindering reliable interpretation of data and the ability to compare results between studies. The experimental research provided further insight by specifically identifying two key factors that influence the outcomes of bioassays: mosquito dry weight and relative humidity (RH). This finding not only advances our comprehension of these assays but also underscores the importance of establishing precisely defined methodologies for resistance monitoring. The study also demonstrates the importance of controlling bioassay variables, noting the significant influence of wing length, as an indicator of mosquito size, on mortality rates in standardized bioassays. Conclusions Generating data with improved protocol consistency and precision will not only deepen our understanding of resistance patterns but also better inform vector control measures. We call for continued research and collaboration to refine and build consensus on bioassay techniques, to help bolster the global effort against vector-borne diseases like malaria.

Two highly selected mutations in the tandemly duplicated CYP6P4a and CYP6P4b genes drive pyrethroid resistance in Anopheles funestus in West Africa

BackgroundGaining a comprehensive understanding of the genetic mechanisms underlying insecticide resistance in malaria vectors is crucial for optimising the effectiveness of insecticide-based vector control methods and developing diagnostic tools for resistance management. Considering the heterogeneity of metabolic resistance in major malaria vectors, the implementation of tailored resistance management strategies is essential for successful vector control. Here, we provide evidence demonstrating that two highly selected mutations in CYP6P4a and CYP6P4b are driving pyrethroid insecticide resistance in the major malaria vector Anopheles funestus, in West Africa.ResultsContinent-wide polymorphism survey revealed escalated signatures of directional selection of both genes between 2014 and 2021. In vitro insecticide metabolism assays with recombinant enzymes from both genes showed that mutant alleles under selection exhibit higher metabolic efficiency than their wild-type counterparts. Using the GAL4-UAS expression system, transgenic Drosophila flies overexpressing mutant alleles exhibited increased resistance to pyrethroids. These findings were consistent with in silico predictions which highlighted changes in enzyme active site architecture that enhance the affinity of mutant alleles for type I and II pyrethroids. Furthermore, we designed two DNA-based assays for the detection of CYP6P4a-M220I and CYP6P4b-D284E mutations, showing their current confinement to West Africa. Genotype/phenotype correlation analyses revealed that these markers are strongly associated with resistance to types I and II pyrethroids and combine to drastically reduce killing effects of pyrethroid bed nets.ConclusionsOverall, this study demonstrated that CYP6P4a and CYP6P4b contribute to pyrethroid resistance in An. funestus and provided two additional insecticide resistance molecular diagnostic tools that would contribute to monitoring and better management of resistance.

Organic vs. Conventional Milk: Uncovering the Link to Antibiotic Resistance in Bacillus cereus sensu lato.

Bacillus cereus sensu lato (B. cereus s.l.) comprises mesophilic and psychrotolerant bacteria commonly found in natural environments as well as in organic and conventional milk. Due to their potential toxigenicity and antibiotic resistance, these bacteria pose a significant threat to consumer health. Organic milk production, which prohibits the use of antibiotics and artificial additives, may influence the composition of microbiota between milk types. This study aimed to compare the antibiotic resistance profiles and enterotoxic potential of B. cereus s.l. isolates from organic and conventional milk. The results indicate that, although conventional milk contains on average 3 times fewer B. cereus s.l. isolates, it has 10-15% more resistant isolates to selected beta-lactams, macrolides, and aminoglycosides. Regarding drug resistance, 21% of B. cereus s.l. isolates were multidrug-resistant, and as many as 42% were non-susceptible to two classes of antibiotics. Even among the sensitive isolates, bacteria from conventional milk exhibited on average 2.05 times higher MICs (minimal inhibitory concentrations) for beta-lactams, 1.49 times higher for erythromycin, 1.38 times higher for vancomycin, and 1.38 times higher for azithromycin. Antibiotic resistance was mostly associated with the origin of the isolates. These findings underscore the need for ongoing monitoring of antibiotic resistance and enterotoxicity among opportunistic B. cereus s.l. strains, which may pose challenges for public health and veterinary medicine. The results highlight that selective pressure associated with antibiotic use can drive resistance development in bacteria that are not the primary targets of antimicrobial therapy.

Real-world studies of crizotinib in patients with ROS1-positive non-small-cell lung cancer: experience from China.

The treatment of non-small-cell lung cancer (NSCLC) has progressed from histology-oriented cytotoxic therapy to the era of molecular biology-oriented targeted therapy and immunotherapy. As the first tyrosine kinase inhibitor (TKI) targeting the ROS1 pathway, crizotinib is widely used as a first-line regimen for ROS1-rearranged NSCLC. However, due to the paucity of solid data from randomized, controlled phase III clinical studies, clinicians often require more systematic, real-world data-based guidance for its optimal clinical use. As one of the leading countries of real-world research on crizotinib, China has contributed significantly to data on standardization of the therapeutic use of crizotinib, including its clinical treatment patterns, the timing and duration of treatment and drug resistance monitoring and management.

Impact of field evolved resistance on biological parameters of non-targeted Aedes aegypti populations.

The yellow fever mosquito, Aedes aegypti L., known for transmitting viruses causing yellow fever, dengue, chikungunya, and Zika fever, presents a substantial risk to global human health. The development of insecticide resistance in disease vectors has become a significant problem in Ae. aegypti. Monitoring insecticide resistance is essential for resistance management in Ae. aegypti. This study involved the collection of Ae. aegypti populations from four important cotton-growing regions in southern Punjab, Pakistan, for resistance monitoring over a two-year period (2021-2022). This study also assessed the impact of insecticide resistance on biological parameters of Ae. aegypti. Moderate-to-high levels of resistance were observed against all the tested insecticides viz., chlorpyrifos, chlorfenapyr, deltamethrin, flonicamid, spirotetramat, and spinetoram. However, compared to the Lab-susceptible population, higher levels of resistance to buprofezin (59.03-84.40) and imidacloprid (68.49-100.01) were found in all populations. This high resistance can be attributed to increased use of these two insecticides in cotton fields, as compared to other insecticides. In the lab-susceptible population, higher values for the intrinsic rate of increase (r) and the net reproductive rate (R0) i.e., 0.20 per day and 23.24 offspring/female were observed, respectively. This was also validated by population projection data where more than 2.5-fold adults (1,020,361.80 individuals) were calculated in the Lab-susceptible population as compared to the most resistant populations. Sublethal exposure to insecticides may induce physiological or biochemical changes in organisms, subsequently influencing the biological traits. Resistance monitoring provides essential guidance before launching a successful chemical-based vector management program.

Plasma cell-free DNA chromatin immunoprecipitation profiling depicts phenotypic and clinical heterogeneity in advanced prostate cancer.

Cell phenotype underlies prostate cancer presentation and treatment resistance and can be regulated by epigenomic features. However, the osteotropic tendency of prostate cancer limits access to metastatic tissue, meaning most prior insights into prostate cancer chromatin biology are from preclinical models that do not fully represent disease complexity. Noninvasive chromatin immunoprecipitation of histones in plasma cell-free in humans may enable capture of disparate prostate cancer phenotypes. Here, we analyzed activating promoter- and enhancer-associated H3K4me2 from cfDNA in metastatic prostate cancer enriched for divergent patterns of metastasis and diverse clinical presentation. H3K4me2 density across prostate cancer genes, accessible chromatin, and lineage-defining transcription factor binding sites correlated strongly with circulating tumor DNA (ctDNA) fraction-demonstrating capture of prostate cancer-specific biology and informing the development of a statistical framework to adjust for ctDNA fraction. Chromatin hallmarks mirrored synchronously measured clinico-genomic features: bone versus liver-predominant disease, serum PSA, biopsy-confirmed histopathological subtype, and RB1 deletions convergently indicated phenotype segregation along an axis of differential androgen receptor activity and neuroendocrine identity. Detection of lineage switching after sequential progression on systemic therapy in select patients indicates potential utility for individualized resistance monitoring. Epigenomic footprints of metastasis-induced normal tissue destruction were evident in bulk cfDNA from two patients. Finally, a public epigenomic resource was generated using a distinct chromatin marker that has not been widely investigated in prostate cancer. These results provide insight into the adaptive molecular landscape of aggressive prostate cancer and endorse plasma cfDNA chromatin profiling as a biomarker source and biological discovery tool.

Determination of antimicrobial resistance genes in patients with infected miscarriage. A rapid identification and optimized empirical therapy

BACKGROUND: The infectious factor during pregnancy remains the leading cause not only of maternal mortality, but also of premature pregnancy loss and subsequent reproductive function impairment. Patients with infected miscarriage represent a special cohort in terms of complexity of clinical decision-making, while the choice of antimicrobial chemotherapy is particularly difficult in conditions of accumulation of scientific knowledge about the main microbial agents. For adequate treatment, it is essential to use all modern methods of microbiota diagnosis and conduct regular monitoring of microorganism resistance in order to update empirical schemes of antibacterial therapy. AIM: The aim of this study was to evaluate the correlation relationship between antimicrobial resistance genes and identified microbial agents in patients with infected miscarriage in order to optimize empirical antimicrobial chemotherapy. MATERIALS AND METHODS: We prospectively studied 42 samples of genital tract discharge in patients with infected miscarriage. The classical culture method was used to determine microorganism sensitivity to standard antibacterial drugs by the disc diffusion test. A molecular genetic study of the species composition of clinically significant microbial agents and genes of resistance to β-lactam and glycopeptide antibiotics was performed using Femoflor Screen and BakRezista GLA test systems (“DNA-Technology” LLC., Russia), respectively. RESULTS: In the cultural study, one microbial agent was identified in 59.5% of cases, two in 40.0% of cases, and three in 7.1% of cases. The following microorganisms were most frequently identified: Enterococcus spp. in 25.0% of cases, Esherichia coli in 16.7% of cases, and Candida spp. in 11.7% of cases. During the molecular genetic study, Lactobacillus spp. were identified in 64.3% of the samples, the microorganisms associated with bacterial vaginosis in 45.3% of the samples, Candida spp. in 23.8% of the samples, and Herpesviridae family viruses in 14.3% of the samples. In 45.2% of the samples, one to 14 genes of resistance to β-lactam and glycopeptide antibiotics were identified, while Tem (19.0%), Oxa-40-like (19.0%), Stx-M1 (14.3%), Ges (14.3%), Oxa-51-like (11.9%), and Van A/B (9.5%) were most frequently determined in the samples positive for resistance genes. Comparison between phenotypic susceptibility testing and genetic prediction for antibiotics resistance demonstrated that the specificity varied from 96.4 to 100%, and the sensitivity from 40.0 to 85.7%. CONCLUSIONS: The use of molecular genetic diagnostic methods allows for the identification of clinically significant urogenital tract infections and the detection of markers of their resistance to β-lactam antibiotics and glycopeptides in the shortest possible time. The data obtained make it possible to optimize the initial antimicrobial chemotherapy.

Trends in Bacterial Distribution and Antimicrobial Resistance in Intensive Care Units of Hubei Province, China: A Four-year Surveillance Study (2020-2023).

To investigate the distribution characteristics of common bacteria and changes in antimicrobial resistance in intensive care unit (ICU) patients in 58 hospitals in Hubei Province from 2020-2023. The antimicrobial agents for antimicrobial susceptibility tests was selected based on the 2022 China Antimicrobial Resistance surveillance system (CARSS) technical scheme, and the specific experimental operation was based on the requirements of the CLSI M02 and M07 documents. The commercial instruments were used following the manufacturer's instructions. The interpretation of antimicrobial susceptibility test results was based on the 2023 CLSI M100 standard. There were 15 585, 19 258, 23 423 and 22 395 clinical isolates in the ICU from 2020 to 2023, respectively. Among them, gram-positive bacteria accounted for 20.5% (3190/15 585), 21.2% (4089/19 258), 21.6% (5067/23 423) and 21.6% (4 831/22 395), respectively. Gram-negative bacteria accounted for 79.5% (12 395/15 585), 78.8% (15 169/19 258), 78.4% (18 356/23 423) and 78.4% (17 564/22 395) of the bacteria, respectively. The top 5 isolates of gram-positive bacteria were Staphylococcus aureus, Enterococcus faecium, Streptococcus pneumoniae, Enterococcus faecalis, Staphylococcus epidermidis and gram-negative bacteria were Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Stenotrophomonas maltophil, respectively, but the proportions and rankings of the isolates in different years slightly differed. The detection rate of methicillin-resistant S. aureus (MRSA) decreased from 44.4% in 2020 to 36% in 2023, and that of methicillin-resistant coagulase-negative Staphylococcus (MRCNS) decreased from 79.8% in 2020 to 73.8% in 2022 and increased to 78.4% in 2023. The detection rates of both vancomycin-resistant E. faecium and E. faecalis were lower than 1%. The detection rate of carbapenem-resistant P. aeruginosa (CRPA) decreased from 25% in 2020 to 19.7% in 2022 and increased slightly to 20.6% in 2023. The detection rate of carbapenem-resistant A. baumannii (CRAB) decreased from 81.9% in 2020 to 79.7% in 2022 and increased to 82.9% in 2023. The detection rate of third-generation cephalosporin-resistant E. coli decreased from 59.8% in 2020 to 53.1% in 2022 and increased to 52.5% in 2023. The detection rate of fluoroquinolone-resistant E. coli decreased from 62.7% in 2020 to 50.2% in 2022 and increased slightly to 51.0% in 2023. The detection rate of carbapenem-resistant E. coli (CRECO) decreased from 3.3% in 2020 to 1.8% in 2022 and slightly increased to 2.1% in 2023. The detection rate of third-generation cephalosporin-resistant K. pneumoniae decreased from 34.3% in 2020 to 26.3% in 2022 and then increased to 32.4% in 2023. The detection rate of carbapenem-resistant K. pneumoniae (CRKPN) increased from 17.9% to 19.4% in 2020, decreased to 13.2% in 2022, and rose sharply to 20.4% in 2023. MRSA showed a continuous downwards trend from 2020 to 2023, while the detection rates of MRCNS and most multidrug-resistant gram-negative bacteria continuously decreased from 2020 to 2022 but tended to increase in 2023. Therefore, it is still necessary to strengthen the monitoring of bacterial resistance and rational application of antibiotics and actively and effectively control nosocomial infections.

An efficient cross-borehole direct current resistivity monitoring instrument

An efficient cross-borehole direct current resistivity monitoring instrument

Using dynamic resistance to predict electrode surface degradation in resistance spot welding of 5182 aluminum alloy

AbstractIn this study, the correlation between dynamic resistance during the first 10 ms of welding time and the electrode surface condition in resistance spot welding of 5182 aluminum alloy has been investigated. The electrode surface rapidly degrades due to contamination and morphological changes, adversely affecting the weld spot surface. The accumulation of Cu-Al intermetallic phases on the electrode surface alters its roughness, leading to variations in dynamic resistance. By analyzing this correlation, optimal electrode milling intervals were identified to extend electrode life. This work focused on detecting crater formation on the electrode surface through dynamic resistance monitoring. The results indicate that resistance measurements provide a reliable approach for evaluating electrode wear, optimizing maintenance schedules, and reducing material removal during milling.

Three-dimensional reconstruction of asphalt road surface texture based on binocular stereo vision

The texture of asphalt pavement plays a pivotal role in ensuring the safe operation of roads. This paper presents a binocular stereo vision hardware system that is designed to acquire asphalt pavement texture features in an economical and efficient manner. The system comprises an image acquisition device, a micro meter, and a camera bracket. The binocular camera baseline length is first determined according to the adjusted camera parameters, with the objective of enhancing the quality of the acquired images. Secondly, the camera calibration was carried out using Matlab and Python software, and the camera parameters were obtained to perform aberration and stereo corrections on the binocular image pairs. Finally, based on Python software, the sum of absolute differences, symmetric diagonal dominance, zero-mean normalised cross-correlation and semi-global block matching algorithms were applied to stereo-match the texture information image set and reconstructed the 3D asphalt pavement point cloud based on parallax mapping. However, it should be noted that the experiment does not consider the effect of light intensity in indoor and outdoor environments. This paper provides a preliminary summary of the current structural design and experiments, and further discusses ideas for subsequent research and improvement. Research and experiments show that the binocular stereo vision imaging system proposed in this paper can effectively match binocular images and present 3D information of asphalt pavement texture. When the binocular camera baseline distance is 40 mm, the maximum calibration error and the average calibration error are both the smallest, which enhances the stability of binocular matching. Furthermore, the camera parameters calculated by the Matlab toolbox calibration are more stable than those obtained by OpenCV calibration. In the indoor experimental environment, the running speeds of the four stereo matching algorithms were compared. In the indoor test environment, the SGBM algorithm was the fastest, with a running speed of 3 seconds, in the order of SGBM>SAD>SSD>ZNCC. The SGBM algorithm demonstrated the most effective parallax mapping reconstruction of asphalt pavement point clouds. The reconstruction of pavement texture may be employed in the future for the real-time monitoring of asphalt pavement skid resistance.

Advanced single-cell and spatial analysis with high-multiplex characterization of circulating tumor cells and tumor tissue in prostate cancer: Unveiling resistance mechanisms with the CoDuCo in situ assay

BackgroundMetastatic prostate cancer is a highly heterogeneous and dynamic disease and practicable tools for patient stratification and resistance monitoring are urgently needed. Liquid biopsy analysis of circulating tumor cells (CTCs) and circulating tumor DNA are promising, however, comprehensive testing is essential due to diverse mechanisms of resistance. Previously, we demonstrated the utility of mRNA-based in situ padlock probe hybridization for characterizing CTCs.MethodsWe have developed a novel combinatorial dual-color (CoDuCo) assay for in situ mRNA detection, with enhanced multiplexing capacity, enabling the simultaneous analysis of up to 15 distinct markers. This approach was applied to CTCs, corresponding tumor tissue, cancer cell lines, and peripheral blood mononuclear cells for single-cell and spatial gene expression analysis. Using supervised machine learning, we trained a random forest classifier to identify CTCs. Image analysis and visualization of results was performed using open-source Python libraries, CellProfiler, and TissUUmaps.ResultsOur study presents data from multiple prostate cancer patients, demonstrating the CoDuCo assay’s ability to visualize diverse resistance mechanisms, such as neuroendocrine differentiation markers (SYP, CHGA, NCAM1) and AR-V7 expression. In addition, druggable targets and predictive markers (PSMA, DLL3, SLFN11) were detected in CTCs and formalin-fixed, paraffin-embedded tissue. The machine learning-based CTC classification achieved high performance, with a recall of 0.76 and a specificity of 0.99.ConclusionsThe combination of high multiplex capacity and microscopy-based single-cell analysis is a unique and powerful feature of the CoDuCo in situ assay. This synergy enables the simultaneous identification and characterization of CTCs with epithelial, epithelial-mesenchymal, and neuroendocrine phenotypes, the detection of CTC clusters, the visualization of CTC heterogeneity, as well as the spatial investigation of tumor tissue. This assay holds significant potential as a tool for monitoring dynamic molecular changes associated with drug response and resistance in prostate cancer.