Drug Susceptibility Testing Research Articles

Global adoption of 6-month drug-resistant TB regimens: Projected uptake by 2026.

The WHO has issued a call to action urging countries to accelerate the rollout of new WHO-recommended shorter all-oral treatment regimens for drug-resistant TB (DR-TB), which remains a public-health crisis. The all-oral, 6-month BPaL/M regimen comprises 3-4 drugs: pretomanid used in combination with bedaquiline and linezolid, with or without moxifloxacin. This regimen has been recommended by the WHO for use in DR-TB patients instead of ≥9-month (up to 24-month) regimens. This study aims to project this regimen's use, along with its components bedaquiline, pretomanid and linezolid, and other treatments for DR-TB globally through 2026. It is intended to guide global health stakeholders in planning and budgeting for DR-TB interventions. Projected usage could help estimate cost of the individual components of DR-TB regimens over time. Semi-structured interviews were conducted with national TB programme participants in key countries to gather intelligence on established plans and targets for use of various DR-TB treatment regimens from 2023 to 2026. These data informed development of projections for the global use of regimens and drugs. Consistent global growth in the use of shorter regimens in DR-TB treatment was shown: BPaLM reaching 126,792 patients, BPaL reaching 43,716 patients, and the 9-11-month all-oral bedaquiline-based regimen reaching 13,119 patients by 2026. By 2026, the longer all-oral regimen is projected to be used by 19,262 patients, and individualised treatment regimens by 15,344 patients. The study shows BPaL/M will be used in majority of DR-TB patients by 2024, reaching 78% by 2026. However, national efforts to scale-up, case-finding, monitoring, drug-susceptibility testing, and implementation of new treatments will be essential for ensuring they are accessible to all eligible patients in the coming years and goals for ending TB are met. There is an urgent need to engage communities in capacity building and demand generation.

Evaluation of the antibacterial effect of Epigallocatechin gallate on the major pathogens of canine periodontal disease and therapeutic effects on periodontal disease mice.

Periodontal disease (PD) is a prevalent oral affliction in canines, with limited therapeutic options available. The potential transmission of oral bacteria from canines to humans through inter-species contact poses a risk of zoonotic infection. Epigallocatechin gallate (EGCG), the principal catechin in green tea polyphenols, exhibits antibacterial properties effective against human PD. Given the clinical parallels between canine and human PD, this study explores the feasibility of employing EGCG as a therapeutic agent for canine PD. Initially, a survey and statistical analysis of bacterial infection data related to canine PD in China were conducted. Subsequently, the primary pathogenic bacteria of canine PD were isolated and cultivated, and the in vitro antibacterial efficacy of EGCG was assessed. Furthermore, verify the therapeutic effect of EGCG on a mouse PD model in vivo. The high-throughput 16S rRNA gene sequencing identified Porphyromonas, Fusobacterium, Treponema, Moraxella, and Capnocytophaga as the genera that distinguishing PD from healthy canines' gingival crevicular fluid (GCF) samples in China. The anaerobic culture and drug susceptibility testing isolated a total of 92 clinical strains, representing 22 species, from 72 canine GCF samples, including Porphyromonas gulae, Prevotella intermedia, Porphyromonas macacae, etc. The minimum inhibitory concentration (MIC) ranging of EGCG was from 0.019 to 1.25 mg/mL. Following a 7 days oral mucosal administration of medium-dose EGCG (0.625 mg/mL), the abundance of periodontal microorganisms in PD mice significantly decreased. This intervention ameliorated alveolar bone loss, reducing the average cementoenamel junction to the alveolar bone crest (CEJ-ABC) distance from 0.306 mm ± 0.050 mm to 0.161 mm ± 0.026 mm. Additionally, EGCG (0.3125 mg/mL) markedly down-regulated the expression of inflammatory factor IL-6 in the serum of PD mice. Our research demonstrates the significant antibacterial effects of EGCG against the prevalent bacterium P. gulae in canine PD. Moreover, EGCG exhibits anti-inflammatory properties and proves effective in addressing bone loss in a PD mouse model. These findings collectively suggest the therapeutic potential of EGCG in the treatment of canine PD. The outcomes of this study contribute valuable data, laying the foundation for further exploration and screening of alternative antibiotic drugs to advance the management of canine PD.

Mutations in the promoter region of methionine transporter gene metM (Rv3253c) confer para-aminosalicylic acid (PAS) resistance in Mycobacterium tuberculosis.

Tuberculosis (TB) is a significant global public health threat. Despite the long-standing use of para-aminosalicylic acid (PAS) as a second-line anti-TB drug, its resistance mechanism remains unclear. In this study, we isolated 90 mutants of PAS-resistant Mycobacterium tuberculosis (MTB) H37Ra in 7H11 solid medium and performed whole-genome sequencing, gene overexpression, transcription level comparison and amino acid level determination in MTB, and promoter activity by β-galactosidase assays in Mycobacterium smegmatis to elucidate the mechanism of PAS resistance. Herein, we found that 47 of 90 (52.2%) PAS-resistant mutants had nine different mutations in the intergenic region of metM (Rv3253c) and Rv3254. Beta-galactosidase assays confirmed that mutations increased promoter activity only for metM but not Rv3254. Interestingly, overexpression of MetM or its M. smegmatis homolog (MSMEI_1796) either by its promoter in metM's direction or by exogenous expression in MTB induced PAS resistance in a methionine-dependent manner. Therefore, drug susceptibility results for the metM promoter mutants can be misleading when using standard 7H10 or 7H9 medium, which lacks methionine. At the metabolism level, PAS treatment led to higher intracellular methionine levels in the mutants than the wild type, antagonizing PAS and conferring resistance. Furthermore, 12 different mutations in the metM promoter were identified in clinical MTB strains. In summary, we found a novel mechanism of PAS resistance in MTB. Mutations in the metM (Rv3253c) promoter upregulate metM transcription and elevate intracellular methionine, which antagonize PAS. Our findings shed new light on the mechanism of PAS resistance in MTB and highlight issues with the current PAS susceptibility culture medium.IMPORTANCEAlthough para-aminosalicylic acid (PAS) has been used to treat TB for more than 70 years, the understanding of PAS resistance mechanisms is still vague, living gaps in our ability to predict resistance and apply PAS effectively in clinical practice. This study aimed to address this knowledge gap by inducing in vitro PAS resistance in Mycobacterium tuberculosis (MTB) using 7H11 medium and discovering a new PAS resistance mechanism. Our research revealed that spontaneous mutations occurring in the promoter region of the methionine transporting gene, metM, can upregulate the expression of metM, resulting in increased intracellular transport of methionine and consequently high-level resistance of Mycobacterium tuberculosis to PAS. Notably, this resistance phenotype cannot be observed when using the commonly recommended 7H10 medium, possibly due to the lack of additional methionine supply compared with that when using the 7H11 medium. Mutations on the regulatory region of metM were also found in some clinical MTB strains. These findings may have important implications for the unexplained PAS resistance observed in clinical settings and provide insight into the failures of PAS treatment. Additionally, they underscore the importance of considering the choice of culture media when conducting drug susceptibility testing for MTB.

Genetic structure and drug resistance of <i>Mycobacterium tuberculosis</i> strains in the Kemerovo Region — Kuzbass

Background. Kemerovo Region has a high burden of tuberculosis (TB) with incidence rates twice the national average. The circulating variants of Mycobacterium tuberculosis significantly influence the TB epidemic process. Screening of epidemically significant variants of the pathogen in areas with a high burden of TB underlies epidemiological diagnosis and is necessary for the development of effective prevention measures. However, the population structure of M. tuberculosis in the Kemerovo Region — Kuzbass is poorly understood.
 Aims: to study genetic heterogeneity and phenotypic resistance to anti-tuberculosis drugs of M. tuberculosis strains in the Kemerovo Region.
 Materials and methods. The MIRU-VNTR genotyping of 163 M. tuberculosis strains isolated from TB patients in the Kemerovo Region in March–October 2022 was carried out. Cultivation of M. tuberculosis, drug susceptibility testing, and isolation of genomic DNA were carried out by standard methods. Genotypic identification was performed using MIRU-VNTR (24 loci) typing. In parallel, express genotyping was carried out: identification of isolates of the Beijing genotype (by RD105/207) and non-Beijing; subtyping Beijing using real-time PCR tests for detection of Central Asian Russian and B0/W148; identification of the non-Beijing group by real-tine PCR RT tests for LAM, S, Ural.
 Results. The isolates of the Beijing genotype (67.5%) were found to dominate both among newly diagnosed (64.4%) and previously treated patients (88.5%). MIRU-VNTR typing revealed 75 profiles, of which 94-32 (35.3%) and 100-32 (15.7%) were the most abundant and belonged to the Beijing genotype. Overall, 39.9% and 20.9% of isolates, respectively, were assigned to the Beijing Central Asian Russian and B0/W148 epidemic clusters, which differed significantly in MDR levels (50.8% and 85.3%, respectively; p = 0.005). The second most common were strains of the genetic family of the Euro-American lineage (L4) (31.9%): LAM (6.7%) Ural (7.4%) Haarlem (4.9%) and L4-unclassified (12.9%), MDR among of these minor genotypes was significantly lower than among Beijing genotype strains, and amounted to 11.5% (p 0.001). Strains from HIV-TB patients (56.4% of the total sample) carried an MDR profile more often (54.8%) compared to TB cases without HIV infection (35.2%) (p = 0.005), which may be due to higher proportion of Beijing genotype strains in the HIV-TB group (75.0% vs. 57.7%; p = 0.026). Complete comparability of the SNP analysis (in-house tests) to identify the main genotypes and epidemically significant Beijing subtypes was shown, which made it possible to characterize 75.5% of the sample by the express method.
 Conclusions. The molecular genetic screening carried out in the Kemerovo Region revealed the heterogeneity of the M. tuberculosis population, which was dominated by strains of the Beijing genotype, with the frequency of subtypes comparable with other territories of the Siberian Federal District.

Rapid detection of drug-resistant Mycobacterium tuberculosis by Modified MODS assay suitable for resource-poor settings.

Cross contamination and biosafety are concerns with the microscopic observation drug susceptibility assay. To address these issues, we modified the MODS technique in the current study. Two hundred and seventy-five samples were processed on LJ media and drug susceptibility was performed by the Indirect agar proportion method. A modified MODS test was done in tissue culture bottles. GenoType MTBDRplus assay was performed to detect the resistance and mutational pattern associated with the resistances. Sensitivity, specificity, positive predictive value, and negative predictive value for the detection of tuberculosis by modified MODS were 97.44%, 80.00%, 97.44%, and 80.00% respectively. The perfect agreement was seen between modified MODS and the Indirect agar proportion method for drug susceptibility testing of isoniazid (kappa = 0.923) and rifampicin (kappa = 1). The contamination rate, cost and TAT for modified MODS were less as compared to the solid media. In the case of MDR-TB isolates S531L (66.66%) was the most prevalent mutation in the rpoB gene followed by S315T2 mutation (58.33%) and T8C (41.66%) in katG and inhA gene respectively. In hetero-resistant strains, C-15T mutation (37.50%) was the most common followed by A-16G (12.50%) in the inhA gene. In INH mono-resistant strains only two mutations were observed i.e., S-315T1(50%) and C-15T (50%) in the katG and inhA genes respectively. Modified MODS proved to be cost-effective and user-friendly, with minimal risk to the handler and no cross-contamination between samples were observed. Hence, it can be used in low-income countries for early detection of tuberculosis and its resistance.

Diagnostic Performance and Comparative Analysis of Conventional Drug Susceptibility Testing, Line Probe Assay, and GeneXpert in Extrapulmonary Tuberculosis Cases: A Cross-sectional Observational Study

Introduction: Tuberculosis (TB), a known threat to mankind for ages, causes a significant burden on healthcare worldwide. The alarming rise of Extrapulmonary Tuberculosis (EPTB) has led healthcare professionals to opt for molecular diagnostics. Despite the availability of rapid diagnostics, conventional culture Drug Susceptibility Testing (DST) is still considered the gold standard in diagnosing TB. Aim: To assess the diagnostic accuracy of culture DST which is considered the gold standard. Materials and Methods: This cross-sectional observational study included 150 suspected EPTB patients and was conducted over a period of one year (September 2018 to August 2019) at Lokmanya Tilak Municipal Medical College and Sion Hospital (LTMMC), a tertiary care hospital in central Mumbai, Maharashtra, India. The hospital is located adjacent to Dharavi, the largest slum area with a high population density, which contributes to the majority of patients attending clinics. Patients attending the pulmonary medicine Outpatient Department (OPD) with extrapulmonary manifestations and suspected cases of EPTB were enrolled in the study. Samples, excluding sputum, were sent to the Department of Microbiology, LTMMC, Sion Hospital for GeneXpert analysis. The samples were further evaluated by microscopy, GeneXpert, and culture DST to detect the presence of Mycobacterium tuberculosis (M. tuberculosis) and drug susceptibility, respectively. Patients positive for Pulmonary Tuberculosis (PTB) were excluded from the study. Categorical variables were described using percentages. A Chi-square test was applied, and a p-value of <0.05 was considered significant. All statistical analyses were performed using SPSS statistical software (IBM SPSS version 26.0, Armonk, N.Y.). Results: Out of the 150 extrapulmonary samples, 23 (15.33%) samples were culture positive for M. tuberculosis and were subjected to DST using the 1% proportion method and GeneXpert assay. The MDR isolates were tested using the firstline Line Probe Assay (LPA). Eleven (47.8%) showed resistance to first-line antitubercular drugs. Among the 12 new cases, only 2 (16.7%) showed resistance compared to 9 (81.8%) in previously treated cases. A discordance of 8.7% was observed between DST with GeneXpert and LPA. Additionally, a discordance of 8.7% was observed between DST and LPA for rifampicin resistance and 4.3% for isoniazid resistance. Conclusion: The paucibacillary nature of extrapulmonary samples contributes to the challenging diagnosis of EPTB cases, leading to increased drug resistance. Highlighting the importance of the conventional solid culture DST method, this study strongly recommends the use of conventional DST accompanied by LPA for extrapulmonary cases.

Discordance Between Phenotypic and WGS-Based Drug Susceptibility Testing Results for Some Anti-Tuberculosis Drugs: A Snapshot Study of Paired Mycobacterium tuberculosis Isolates with Small Genetic Distance.

Current tuberculosis treatment regimens primarily rely on phenotypic drug susceptibility testing and rapid molecular assays. Although whole-genome sequencing (WGS) offers a promising alternative, disagreements between phenotypic and molecular testing methods remain. In this retrospective study, we compared the phenotypic and WGS-predicted drug resistance profiles of paired Mycobacterium tuberculosis isolates with small genetic distances (≤10 single nucleotide variants) obtained from patients with longitudinal single-episode or recurrent tuberculosis. Additionally, we investigated the distribution of drug-resistance-conferring variants among the identified M. tuberculosis genotypes. Paired M. tuberculosis isolates from 46 patients with pulmonary tuberculosis (2002-2019) were analyzed. Spoligotyping was performed for all the isolates. WGS data were processed using TB-Profiler software to genotype the strains and detect variants in M. tuberculosis genes associated with drug resistance. The significance of these variants was evaluated using the M. tuberculosis variant catalog developed by the World Health Organization. Phenotypic drug susceptibility test results were obtained from patients' medical records. Among the 46 isolate pairs, 25 (54.3%) harbored drug-resistance-associated variants, with 20 demonstrating identical WGS-predicted drug resistance profiles. Drug-resistant isolate pairs belonged to Lineages 2 and 4, with the most common sub-lineages being 2.2.1 (SIT1 and SIT190 spoligotypes), and 4.3.3 (SIT42). Agreement between phenotypic and WGS-based drug susceptibility testing was highest (>90%) for rifampicin, isoniazid, ethambutol, fluoroquinolones, streptomycin, and amikacin when calculated for M. tuberculosis isolates or isolate pairs. In most discordant cases, isolate pairs harbored variants that could cause low- or moderate-level resistance or were previously associated with variable minimum inhibitory concentrations. Notably, such discrepancies mostly occurred in one isolate from the pair. In addition, differences in resistance-related variant distributions among M. tuberculosis genotypes were observed for most of the analyzed drugs. The simultaneous performance of phenotypic and WGS-based drug susceptibility testing creates the most accurate drug resistance profile for M. tuberculosis isolates and eliminates important limitations of each method.

Two-stage tuberculosis diagnostics: combining centrifugal microfluidics to detect TB infection and Inh and Rif resistance at the point of care with subsequent antibiotic resistance profiling by targeted NGS.

Globally, tuberculosis (TB) remains the deadliest bacterial infectious disease, and spreading antibiotic resistances is the biggest challenge for combatting the disease. Rapid and comprehensive diagnostics including drug susceptibility testing (DST) would assure early treatment, reduction of morbidity and the interruption of transmission chains. To date, rapid genetic resistance testing addresses only one to four drug groups while complete DST is done phenotypically and takes several weeks. To overcome these limitations, we developed a two-stage workflow for rapid TB diagnostics including DST from a single sputum sample that can be completed within three days. The first stage is qPCR detection of M. tuberculosis complex (MTBC) including antibiotic resistance testing against the first-line antibiotics, isoniazid (Inh) and rifampicin (Rif). The test is automated by centrifugal microfluidics and designed for point of care (PoC). Furthermore, enriched MTBC DNA is provided in a detachable sample tube to enable the second stage: if the PCR detects MTBC and resistance to either Inh or Rif, the MTBC DNA is shipped to specialized facilities and analyzed by targeted next generation sequencing (tNGS) to assess the complete resistance profile. Proof-of-concept testing of the PoC test revealed an analytical sensitivity of 44.2 CFU ml-1, a diagnostic sensitivity of 96%, and a diagnostic specificity of 100% for MTBC detection. Coupled tNGS successfully provided resistance profiles, demonstrated for samples from 17 patients. To the best of our knowledge, the presented combination of PoC qPCR with tNGS allows for the fastest comprehensive TB diagnostics comprising decentralized pathogen detection with subsequent resistance profiling in a facility specialized in tNGS.

Rapid Drug Susceptibility Testing to Preserve Antibiotics.

Antibiotic resistance is a global challenge likely to cost trillions of dollars in excess costs in the health system and more importantly, millions of lives every year. A major driver of resistance is the absence of susceptibility testing at the time a healthcare worker needs to prescribe an antimicrobial. The effect is that many prescriptions are unintentionally wasted and expose mutable organisms to antibiotics increasing the risk of resistance emerging. Often simplistic solutions are applied to this growing issue, such as a naïve drive to increase the speed of drug susceptibility testing. This puts a spotlight on a technological solution and there is a multiplicity of such candidate DST tests in development. Yet, if we do not define the necessary information and the speed at which it needs to be available in the clinical decision-making progress as well as the necessary integration into clinical pathways, then little progress will be made. In this chapter, we place the technological challenge in a clinical and systems context. Further, we will review the landscape of some promising technologies that are emerging and attempt to place them in the clinic where they will have to succeed.

Genotypic and phenotypic drug resistance patterns of Mycobacterium tuberculosis isolated from presumptive pulmonary tuberculosis patients in Ethiopia: A multicenter study.

The emergence of drug-resistant tuberculosis (DR-TB) has been a major obstacle to global tuberculosis control programs, especially in developing countries, including Ethiopia. This study investigated drug resistance patterns and associated mutations of Mycobacterium tuberculosis Complex (MTBC) isolates from the Amhara, Gambella, and Benishangul-Gumuz regions of Ethiopia. A cross-sectional study was conducted using 128 MTBC isolates obtained from patients with presumptive tuberculosis (TB). Phenotypic (BACTEC MGIT 960) and genotypic (MTBDRplus and MTBDRsl assays) methods were used for drug susceptibility testing. Data were entered into Epi-info and analyzed using SPSS version 25. Frequencies and proportions were determined to describe drug resistance levels and associated mutations. Of the 127 isolates recovered, 100 (78.7%) were susceptible to four first-line anti-TB drugs. Any drug resistance, polydrug resistance, and multi-drug resistance (MDR) were detected in 21.3% (27), 15.7% (20), and 15% (19) of the isolates, respectively, by phenotypic and/or genotypic methods. Mono-resistance was observed for Isoniazid (INH) (2, 1.6%) and Streptomycin (STR) (2, 1.6%). There were two genotypically discordant RIF-resistant cases and one INH-resistant case. One case of pre-extensively drug-resistant TB (pre-XDR-TB) and one case of extensively drug-resistant TB (XDR-TB) were identified. The most frequent gene mutations associated with INH and rifampicin (RIF) resistance were observed in the katG MUT1 (S315T1) (20, 76.9%) and rpoB (S531L) (10, 52.6%) genes, respectively. Two MDR-TB isolates were resistant to second-line drugs; one had a mutation in the gyrA MUT1 gene, and the other had missing gyrA WT1, gyrA WT3, and rrs WT1 genes without any mutation. The detection of a significant proportion of DR-TB cases in this study suggests that DR-TB is a major public health problem in Ethiopia. Thus, we recommend the early detection and treatment of DR-TB and universal full first-line drug-susceptibility testing in routine system.

Important Recommendations Regarding the Test-and-Treat Strategy for Helicobacter pylori Infection in Children.

Helicobacter pylori is a commonly encountered pathogen in medical practice. It causes chronic gastritis in patients of different ages. Many published papers have provided different opinions on whether the test-and-treat strategy for H. pylori infection should be implemented in children. It is critical that the opinion in favor of this strategy was published in Europe, where ESPGHAN/NASPGHAN guidelines have not recommended the use of test-and-treat strategy for H. pylori in children. Herein, I propose my opinion regarding this debate using 4 main points. First, this strategy should be implemented in areas where its benefits outweigh the associated risks. Thus, if it is not tailored to the locality, the results of the test-and-treat strategy for H. pylori in children may be erroneous. Second, the association between H. pylori infection and other diseases such as asthma and other allergic diseases should not be factored in when considering the test-and-treat strategy. This is because these diseases are associated with H. pylori noninfection and not with its posteradication status. Third, there is evidence that H. pylori infection can significantly alter children's intestinal microbiota. Finally, gastroscopy should not be performed in all H. pylori-positive children, particularly if the drug susceptibility test is not available. In the near future, it will be possible to easily conduct drug susceptibility tests for H. pylori using fecal samples. I believe that this report may expand the test-and-treat strategy for children infected with asymptomatic H. pylori outside of Japan and prevent not only gastric cancer but also minor diseases such as iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, and failure to thrive. Pediatricians are responsible for keeping children healthy not only during childhood but also in adulthood. Thus, even if there are only a few H. pylori-related diseases and no severe cases in children, it is necessary to take early measures to prevent problems (eg, incidence of gastric cancer) in adulthood.

The performance of Xpert MTB/RIF and MTBDRplus within a Programmatic setting at TB Laboratory in Rio de Janeiro, Brazil.

Few studies in routine settings have confirmed the high accuracy of the Xpert MTB/RIF assay for detecting rifampicin resistance (RR) and the first-line probe assay (FL-LPA) for detecting both RR and isoniazid resistance (INHR). The performance of Xpert MTB/RIF and MTBDRplus VER 2.0 LPA was evaluated in 180 Mycobacterium tuberculosis samples collected from January 2018 to December 2019 in Rio de Janeiro, Brazil. The results were compared with those from BACTEC MGIT 960 culture and drug susceptibility testing (DST). Whole-genome sequencing was performed on the samples with discordant results. The Xpert MTB/RIF assay showed a sensitivity (Se) of 93.3% and a specificity (Sp) of 97.6%, detecting RR. The performance of FL-LPA to identify RIF and INH resistance was, respectively, (Se) 100% and 83.3% and (Sp) 98.8% and 100%. Among 18 clinical isolates with INHR detected by FL-LPA, mutations in the katG gene were observed in 100% of samples, of which only two (11.1%) had mutations in both katG and inhA genes. Overall, the discordant results were identified in 9 (5%) samples. Among the four Xpert RIF-resistant and DST-sensitive, two harbored mutations in rpoB Leu430Pro. Among the four FL-LPA-sensitive and DST-resistant, one had a mutation in inhA 17G>T. FL-LPA showed high accuracy in detecting RR and INHR. The MTBDRplus test demonstrated excellent performance in detecting RR, and INHR in clinical isolates under routine conditions at a reference laboratory in Rio de Janeiro, Brazil. Incorporating both tests can improve drug-resistant tuberculosis treatment outcomes and monitor the INHR incidence.

Status and Challenge of Antifungal Stewardship at the Osaka Metropolitan University Hospital.

Antifungal stewardship (AFS), compared with antimicrobial stewardship (AS), requires more advanced knowledge, skills, and multidisciplinary collaboration in its implementation. Therefore, fewer facilities are performing AFS compared with AS. At our hospital, we started AS and AFS in 2014. Our AFS programs include the following: i) interventions for patients with yeast-positive blood cultures, ii) introduction of a conditional antifungal notification system, and iii) commencement of AS team rounds. AFS for filamentous fungi includes bronchoscopy and microbial identification, including genetic and drug susceptibility testing. These AFS activities have improved several processes and outcome measures. However, our AFS team has faced several problems owing to the impact of COVID-19. This review introduces the practice of AFS, which we initiated at our hospital in 2014, and presents the current problems.

Genome‐Based Molecular Diversity of Extended‐Spectrum β‐Lactamase‐Producing Escherichia coli From Pigeons in China

Extended‐spectrum β‐lactamase‐producing Escherichia coli (ESBL‐EC) strains present a significant menace to the well‐being of both animals and humans. However, limited information is available regarding their profiles in pigeons. Using a combination of whole genome sequencing, drug susceptibility testing, and bioinformatics analysis, we examined the genomic features and epidemiology of 95 ESBL‐EC strains (41 racing and 54 meat pigeons) that were isolated from 11 Chinese cities. These strains belonged to seven phylogenetic groups (A, B1, B2, C, D, E, and F). Moreover, these isolates have 51 serotypes, including several pathogenic ones (e.g., O51, O8, O4, O25, and O6). Notably, two high‐risk clones, ST131 O25:H4, were found in racing pigeons and were responsible for the worldwide outbreaks of highly pathogenic and multidrug‐resistant (MDR) E. coli infections. In addition, we found 41 multilocus sequence typing types, of which the dominant types were ST155, ST20, ST1011, and ST1196. In total, 91 isolates (95.79%) showed MDR, while eight isolates (8.42%) showed resistance to up to eight classes of antibiotics. Furthermore, we identified a series of ESBL genes in these isolates, including blaCTX-M, blaTEM, blaOXA, blaLAP, and blaCMY. Also, 50 other antibiotic resistance genes (ARGs) were accompanied by the carriage of 33 plasmid replicon types, facilitating the horizontal spread of ARGs. Interestingly, three mcr-1, four mcr-1.1, and one tet(X4) were found in isolates of meat pigeons, and it was possible to successfully transfer the plasmids containing tet(X4) and mcr-1.1 to E. coli C600. In summary, this work presents the complexity of MDR profiles, plasmid profiles, and multiple typing profiles of Chinese ESBL‐EC isolates of pigeon origin for the first time. The thorough investigation of ESBL‐EC in pigeons presented in this work suggests that racing and meat pigeons are significant ARGs reservoirs.

Study on the Potential Probiotics Isolated from Marine Aquaculture System and Evaluation for Aquaculture Application

In recent years, more attention has been paid to the application of host‐associated microorganisms as an appropriate source of probiotics in aquaculture. These probiotics promoted effective colonization and application and provided better benefits than other sources. A total of 32 isolates were collected from the water, shrimp, and sediment of the cultured pond of Litopenaeus vannamei. Probiotic effects were comprehensively evaluated by extracellular enzyme activity, virulence genes detection, bacteriostatic activity, drug susceptibility test, tolerance to adverse environment, and challenge experiment. Six of these isolates exhibited bacteriostatic activity against pathogens, such as Vibrio cholerae, V. owensii, V. fluvialis, V. campbellii, V. rotiferianus, Photobacterium damselae, V. vulnificus, and V. parahaemolyticus. Using 16S rRNA gene sequencing analysis, isolates were identified as Bacillus subtilis (P8, P29, and P30), B. velezensis (P12), Prestia flexa (P21), and Cytobacillus firmus (P23). They were tolerant to high temperature, low acid (pH 2.0), bile salt (2%), and the simulated gastrointestinal environment, secreting phospholipase, amylase, protease, gelatinase, and lipase. They were sensitive to only two or fewer drugs among 27 antibacterial drugs and did not carry any of the tested virulence genes. Biosafety in vivo evaluations showed that they were safe for Ctenopharyngodon idella (P12 ＞ P23 ＝ P29 ＞ P8 ＞ P30 ＝ P21). The results suggest that P8, P12, P23, P21, P29, and P30 have high probiotic potential and can be used as good probiotics in aquaculture and the development of ecological preparations.

Microbiological and Molecular Study of Paranasal Sinus Infections of Children with Malignancy and Unknown Origin Fever in Markazi Province, Iran

BackgroundChildren with malignancies are vulnerable to various infections, including sinus infections. Sinusitis is primarily caused by bacterial infections, followed by fungal infections. Due to this issue, evaluating the occurrence, diversity, and antibiotic susceptibility patterns of bacterial species that cause paranasal sinus infections in children with malignancy and unexplained fever is important. ObjectiveInvestigate the bacterial species accountable for sinusitis in children with malignancy and unexplained fever, and determine their susceptibility to antibiotics. MethodsThe study involved collecting 90 sinus samples from children aged 5-15 years with malignancy in Arak city. The isolates were identified using a combination of phenotypic, biochemical, and molecular techniques, including specific PCR and 16S rRNA gene sequencing. drug susceptibility testing was performed following the CLSI 2021 guidelines. ResultsA total of 36 isolates (40%) were obtained, including 4 isolates of Nocardia (11.12%), 4 isolates of E. coli (11.12%), 3 isolates of K. pneumoniae (8.33%), 5 isolates of P. aeruginosa (13.88%), 3 isolates of A. baumannii (8.33%), 4 isolates of S. aureus (11.12%), 3 isolates of S. epidermidis (8.33%), 5 isolates of S. agalactiae (13.88%), 2 isolates of S. pneumoniae (5.55%), and 3 isolates of E. faecium (8.33%). The isolates showed the most sensitivity to imipenem and trimethoprim-sulfamethoxazole and the least sensitivity to erythromycin and tetracycline. ConclusionsThe findings of the study indicate that sinusitis can contribute to fever of unknown origin in cancer patients. Therefore, it is recommended to use a combination of molecular and phenotypic methods for accurate identification of isolates. This approach can provide more reliable and precise results, leading to better diagnosis and treatment of sinusitis infections in children with malignancy.

Mutational analysis in drug resistant Mycobacterium tuberculosis in Western Uttar Pradesh

BackgroundMulti-drug resistant tuberculosis (MDR-TB) results in treatment failure and poor clinical outcomes. This study was carried out with the aim to determine the pattern of drug resistance against Mycobacterium tuberculosis towards first line ATT (anti-tubercular treatment) in sputum smear–positive patients using Line Probe Assay (LPA). MethodsA cross sectional prospective study was carried out in a tertiary care Hospital of Meerut. A total of 898 sputum samples (on spot and early morning) collected from 449 suspected pulmonary tuberculosis patients as per RNTCP guidelines were screened by microscopy. Decontamination was done by N-acetyl-l-cysteine and sodium hydroxide. Then smear positive samples were subjected to 1st line drug susceptibility testing (DST) using LPA GenoType® MTBDRplus (HAIN Life Science) assay, a molecular method which allows rapid detection of Rifampicin (Rif) and Isoniazid (INH) resistance. ResultsThe overall burden of MDR TB in this geographical area was 7.9 %. Mono-resistance with Rif alone was around 2.8 %. However, the mono-resistance with INH (inhA gene) and INH (katG gene) was 2.8 % and 1.1 % respectively. Drug resistance of Rif was due to mutations in rpoB gene while resistances to INH were more commonly due to mutation in inhA gene followed by katG gene. TB was more commonly seen in the age group of 30–59 years (43.8 %) and predominantly in males. ConclusionTuberculosis positivity rate is high in Western Uttar Pradesh. Burden of MDR TB in Western Uttar Pradesh was similar to National data. Line probe assay can be used as a primary method to diagnose multi drug resistant TB as done in present study which can help in earlier initiation of correct therapy.

Impact of line probe assay-based molecular testing on individualized treatment in patients with rifampicin-resistant tuberculosis: data from the prospective INNOVA4TB cohort study in Ukraine.

Ukraine remains a high World Health Organization priority country for drug-resistant tuberculosis (TB). Rifampicin-resistant TB (RR-TB) has a more protracted, more complicated, and more expensive treatment. In 2021, Ukraine reported 4025 RR-TB cases - 5.4 times more (751) than all 30 European Union/ European Economic Area countries together. The objective of the study was to determine the diagnostic accuracy of line probe assay (LPA), AID Autoimmun Diagnostika GmbH, for detecting resistance to anti-TB drugs and its clinical application for selecting treatment regimens. A prospective observational cohort study. From May 2019 to June 2020, we consecutively enrolled patients with active TB hospitalized at the Regional Phthisiopulmonology Center (Vinnytsia, Ukraine), aged between 18 and 82 years. The LPA was performed in the Genetic Research Laboratory at National Pirogov Memorial Medical University, Vinnytsia, Ukraine. A total of 84 clinical specimens and 97 culture isolates from 126 TB patients were tested during the study. Accuracy (95% confidence interval) of LPA for clinical samples in comparison with phenotypic drug susceptibility test (DST) was 80.1 (68.5-89.0) for isoniazid (H), 74.7 (62.4-84.6) for rifampicin (R), 74.4 (62.5-84.1) for ethambutol, 71.4 (41.9-91.6) for streptomycin, 84.6 (62.4-96.5) for prothionamide/ethionamide, and 84.6 (73.6-92.3) for levofloxacin (Lfx), respectively. We found a significantly higher sensitivity of LPA for H, R, and Lfx for the culture isolates compared to clinical specimens (p < 0.05). LPA detected different mutations in 6 out of 17 (35.5%) patients susceptible to R by Xpert. A shorter treatment regimen with an injectable agent demonstrated a low suitability rate of 5% (8/156) in a cohort of RR-TB patients from Ukraine. Initial LPA testing accurately identifies resistance to anti-TB drugs and facilitates the selection of an appropriate treatment regimen, minimizing exposure to empirical therapy.

Drug-Resistant Characteristics, Genetic Diversity, and Transmission Dynamics of Multidrug-Resistant Mycobacterium tuberculosis in Jiangxi, China.

In this study, we aimed to determine the transmission pattern of multidrug-resistant tuberculosis (MDR-TB) isolates circulating in Jiangxi Province with whole-genome sequencing (WGS). In addition, we also sought to describe mutational resistome of MDR-TB isolates. A total of 115 MDR-TB isolates determined by the phenotypic proportion method of drug susceptibility testing between January 2018 and December 2022 from provincial drug surveillance (DRS) in Jiangxi were included in our analysis. The demographic data and treatment history were extracted from the National TB Registry System. WGS was used to analyze the genotypic characteristics of drug resistance and transmissions. About 62.6% of MDR-TB strains were isolated from cases that received previous anti-tuberculosis treatment. According to the WGS results, 96.5% were genotypic MDR-TB, and more than half of MDR-TB isolates tested were also resistant to streptomycin (59.1%), ethambutol (56.5%), and fluroquinolones (53.0%), while resistance to cycloserine and linezolid was lowest, only in two (1.7%) and one (0.9%) isolate, respectively. Ser450Leu in rpoB (57.9%), Ser315Thr in katG (74.1%), Met306Val in embB (40.0%), Lys43Arg in rpsL (75.0%), Ala90Val in gyrA (32.8%) were predominant mutant types among the rifampin-, isoniazid-, ethambutol-, streptomycin-, fluoroquinolones-resistant isolates, respectively. Lineage 2 (East Asian genotype) occurred at the highest frequency with 97 cases (84.3%), followed by lineage 4 (Euro-American genotype) with 18 cases (15.7%). Additionally, 5 clusters consisting of 10 isolates were identified in the present study, demonstrating a clustering rate of 8.7%. MDR/Rifampicin-Resistant (RR)-TB epidemic in this region is driven by lineage 2 clade that also show higher resistance to other anti-tuberculosis drugs. Lower cluster rates compared with a relatively higher proportion of new MDR-TB cases indicate that a considerable number of MDR-TB cases remain undiagnosed.

Rapid Detection of M. tuberculosis and Its Resistance to Rifampicin and Isoniazid with the mfloDx™ MDR-TB test.

Rapid detection of tuberculosis (TB) and its resistance are essential for the prompt initiation of correct drug therapy and for stopping the spread of drug-resistant TB. There is an urgent need for increased use of rapid diagnostic tests to control the threat of increased TB and multidrug-resistant TB (MDR-TB). EMPE Diagnostics has developed a multiplex molecular diagnostic platform called mfloDx™ by combining nucleotide-specific padlock probe-dependent rolling circle amplification with sensitive lateral flow biosensors, providing visual signals, similar to a COVID-19 test. The first test kit of this platform, mfloDx™ MDR-TB can identify Mycobacterium tuberculosis (MTB) complex and its clinically significant mutations in the rpoB and katG genes and in the inhA promotor contributing resistance to rifampicin (RIF) and isoniazid (INH), causing MDR-TB. We have evaluated the performance of the mfloDx™ MDR-TB test on 210 sputum samples (110 from suspected TB cases and 100 from TB-negative controls) received from a tertiary care center in India. The clinical sensitivity for detecting MTB compared to acid-fast microscopy and mycobacteria growth indicator tube (MGIT) cultures was 86.4% and 84.9%, respectively. All the 100 control samples were negative indicating excellent specificity. In smear-positive sputum samples, the mfloDx™ MDR-TB test showed a sensitivity of 92.5% and 86.4% against MGIT culture and Xpert MTB/RIF, respectively. The clinical sensitivity for the detection of RIF and INH resistance in comparison with MGIT drug susceptibility testing was 100% and 84.6%, respectively, while the clinical specificity was 100%. From the above evaluation, we find mfloDx™ MDR-TB to be a rapid and efficient test to detect TB and its multidrug resistance in 3 h at a low cost making it suitable for resource-limited laboratories.