Resistance Rates Research Articles

Investigation of in vitro susceptibility and resistance mechanisms to amikacin among diverse carbapenemase-producing Enterobacteriaceae

ObjectiveThis study aims to assess the in vitro drug susceptibility of various Carbapenemase-Producing Enterobacteriaceae (CPE) genotypes and elucidate the underlying mechanisms of amikacin resistance.MethodsA total of 72 unique CPE strains were collected from the Second Hospital of Jiaxing between 2019 and 2022, including 51 strains of Klebsiella pneumoniae, 11 strains of Escherichia coli, 6 strains of Enterobacter cloacae, 2 strains of Klebsiella aerogenes, 1 strain of Citrobacter freundii, and 1strain of Citrobacter werkmanii. Among these strains, 24 carried blaKPC gene, 20 carried blaNDM gene, 23 carried blaOXA−48−like gene, and 5 carried both blaKPC and blaNDM. We measured the in vitro activity of amikacin and other common antibiotics. Strains carrying blaOXA−48-like gene were selected for whole genome sequencing (WGS) via next-generation sequencing to identify genes related to antimicrobial resistance (AMR) and virulence factor (VF).ResultsOut of the 72 CPE strains tested, 41.7% exhibited resistance to amikacin. The drug resistance rates for K. pneumoniae, E. coli, and Enterobacter spp. were 51.0%, 27.3%, and 10.0%, respectively. The majority of the CPE strains (> 90%) displayed resistance to cephalosporins and carbapenems, while most of them were sensitive to polymyxin B and tigecycline (97.2% and 94.4%). The amikacin resistance rate was 100% for strains carrying blaOXA−48, 20.8% for those with blaKPC, 5.0% for those with blaNDM, and 20.0% for those with both blaKPC and blaNDM. These differences were statistically significant (P < 0.05). Through sequencing, we detected aminoglycoside resistance genes rmtF and aac(6’)-Ib, VF genes iucABCD and rmpA2 in OXA-48-producing multidrug resistance and highly virulent strains. These genes were located on a IncFIB- and IncHI1B-type plasmid, respectively. Both plasmids were highly homologous to the plasmid from OXA-232 strains in Zhejiang province and Shanghai province. Integration of these resistance genes into the IncFIB plasmid, facilitated by the IS6 and/or Tn3 transposons, resulted in OXA232-producing K. pneumoniae with amikacin resistance.ConclusionThis study identified significant amikacin resistance in CPE strains, particularly in those carrying the blaOXA−48 gene. Resistance genes rmtF and aac(6’)-Ib were identified on plasmids. These results highlight the need for careful monitoring of amikacin resistance.

Persistent carbapenem resistance in mechanically ventilated ICU patients: A before-and-after analysis of the COVID-19 surge

ObjectiveHow did the antimicrobial resistance profile of critically ill patients evolve before, during, and after COVID-19 surge periods? MethodsWe retrospectively analysed all critically ill mechanically ventilated adult patients admitted to eight Brazilian hospitals from January 1st, 2018, to April 30th, 2023. We stratified the patients into three periods based on their admission date: pre-surge (Jan 01/2018-Mar 01/2020), surge (Mar 01/2020 - Oct 01/2021), and post-surge (after Oct 01/2021). We compared the proportion of positive cultures, prevalence of pathogens, and resistance rates across periods using the rate ratios (RR) and their 95% confidence intervals (95% CI). ResultsWe analysed 9,780 ICU patients: 3,718 were in the pre-surge, 3,815 in the surge, and 2,247 in the post-surge period. Patients in the surge period were younger (median: 70 vs. 74 pre-surge vs. 75 post-surge) and presented a higher duration of invasive mechanical ventilation (median 7 vs. 5 days). The utilisation of blood and respiratory cultures increased throughout periods (56.9 pre-surge vs. 69.4 surge vs. 70.4 patients/1,000 patient days post-surge). The isolation of carbapenem-resistant gram-negative bacteria increased during the surge (RR [95% CI]: 1.8 [1.5-2.2], compared to pre-surge), decreased in post-surge (RR [95% CI]: 0.72 [0.6-0.9], and remained higher than pre-surge (RR [95% CI]: 1.3 [1.0-1.6]). Resistance rates for Pseudomonas aeruginosa reduced from 32% in pre- to 23% post-surge, whereas Klebsiella pneumoniae doubled during the surge, 26% to 52%, and remained higher than pre-surge. ConclusionCarbapenem resistance increased during the surge period. Although it decreased post-surge, it remained higher than the rates observed before the pandemic.

Geographic differences in susceptibility profiles of potential non-class B carbapenemase-producing Enterobacterales isolates against ceftazidime-avibactam, meropenem-vaborbactam, colistin, amikacin, gentamicin, and tigecycline: Data from the Antimicrobial Testing Leadership and Surveillance, 2018–2022

To evaluate the susceptibility profiles of regional meropenem-resistant (MEM-R) potential non-class B carbapenemase-producing Enterobacterales (CPE) isolates (without confirmation by phenotypic tests) against important antibiotics, we extracted data from the 2018-2022 Antimicrobial Testing Leadership and Surveillance. This data included susceptibility information of MEM-R potential non-class B CPE isolates against indicated antibiotics - amikacin [AMK], gentamicin [GM], ceftazidime-avibactam [CZA], colistin [CST], meropenem-vaborbactam [MVB], and tigecycline [TGC] - from sepsis patients hospitalized in ICUs across six major regions. Carbapenemase-encoding genes of the tested CPE isolates, determined by multiplex PCR and Sanger sequencing, were also analyzed. Susceptibility breakpoints recommended by CLSI 2024 and US FDA criteria (for TGC only) against Enterobacterales were employed. A total of 1,500 potential non-class B CPE isolates (89% of which were Klebsiella pneumoniae) were tested globally. Resistance rates to AMK and GM against the evaluated isolates were statistically higher in Africa/the Middle East, Europe, and India compared to other regions. A similar pattern was observed in the susceptibility of these potential CPE isolates to CZA and MVB. High CST resistance rates were noted in Asia, Latin America, and Europe (29%-35%). Furthermore, the proportions of potential CPE isolates carrying genes encoding blaOXA variants were notably higher among the tested CPE isolates in India, Europe, and Africa/the Middle East regions (99.2%, 53.3%, and 96.7%, respectively) compared to other regions. Trends in resistance to important antibiotics among potential non-class B CPE isolates warrant close monitoring.

Prevalence, Risk Factors, and Outcome of Carbapenem-resistant Acinetobacter Infections in a Community Hospital in Madinah, Saudi Arabia

Abstract Background: Acinetobacter is a Gram-negative bacterium that causes nosocomial infections, increasing healthcare costs, patient morbidity, and mortality. The rate of carbapenem resistance among Acinetobacter species is rising in several countries, including Saudi Arabia. Objective: To determine the risk factors and compare the predictors of mortality in patients infected with carbapenem-susceptible and carbapenem-resistant Acinetobacter strains. Materials and Methods: This retrospective study included patients with Acinetobacter infection who were admitted to a community hospital in Madinah, Saudi Arabia, between January 2017 and June 2021. A logistic regression analysis was conducted to assess the risks of acquiring carbapenem-resistant Acinetobacter infections and the mortality risk associated with these infections. Results: This study included 138 Acinetobacter-infected cases, of which 114 (82%) were carbapenem-resistant infections. Between 2017 and 2020, resistance rates increased from 75% to 87%. Patients with carbapenem-resistant Acinetobacter infections had higher 90-day mortality than those with carbapenem-susceptible infection (62% vs. 29%, P = 0.006). The risk factors for carbapenem-resistant Acinetobacter infections were prior antimicrobial therapy (aOR: 8.36 [1.69–41.29]; P = 0.009) and mechanical ventilation (aOR: 6.07 [1.82–20.20]; P = 0.003). Among all patients with Acinetobacter infections, significant predictors of 90-day mortality were carbapenem resistance (aOR: 3.26 [1.19–8.90]; P = 0.021) and Charlson comorbidity score (aOR: 1.19 [1.06–1.34]; P = 0.004). Conclusion: The increase in carbapenem-resistant Acinetobacter cases in this study was consistent with the findings of other studies from Saudi Arabia. This, together with the high associated mortality rates, indicates the urgent need for effective antimicrobials and infection prevention strategies to combat carbapenem-resistant Acinetobacter infections in hospitals.

Computational Exploration of Limonin as a Potential Inhibitor of DapB in Klebsiella pneumoniae.

Klebsiella pneumoniae has emerged as a significant multidrug-resistant pathogen, classified as a critical priority by the World Health Organization. The rising rates of antibiotic resistance have led to increased therapeutic failures, diminishing the effectiveness of existing antibiotics. Consequently, there is an urgent need for alternative treatments to effectively inhibit the growth of K. pneumoniae and mitigate associated diseases. Phytochemicals have demonstrated potential advantages over traditional antibiotics, prompting their exploration as innovative therapeutic agents. This study aimed to identify phytochemicals that can inhibit dapB, a vital enzyme in the lysine biosynthesis pathway of K. pneumoniae, which is essential for protein synthesis and the cross-linking of the bacterial peptidoglycan cell wall. We screened 17,934 phytochemicals based on Lipinski's Rule of Five, along with their Absorption, Distribution, Metabolism, Excretion properties and toxicological parameters. Next, we conducted triplicate docking studies against dapB to evaluate the library further. The most promising molecules then underwent 100 ns Molecular Dynamics simulations in triplicate, followed by binding free energy calculations to identify potential dapB inhibitors. This in silico analysis highlighted limonin as a promising inhibitor of dapB in K. pneumoniae. Further experimental validation is crucial to enhance limonin's potential as a novel therapeutic agent against K. pneumoniae-associated diseases.

Investigating an Outbreak of Extensively Drug-Resistant Acinetobacter baumannii in a Tertiary Healthcare Centre in Lebanon Using Next-Generation Sequencing

The frequent occurrence of Acinetobacter baumannii in hospital settings and the elevated rate of antimicrobial resistance in this pathogen represent a serious clinical and public health threat worldwide, and particularly in Lebanon where outbreak surveillance and control are still insufficient. Whole-genome sequencing (WGS) is a fast and reliable tool to study outbreaks at the molecular level and obtain actionable knowledge, leading to better control measures. A total of 59 A. baumannii isolates were collected from intensive care unit (ICU) patients (57 isolates) and from the hospital environment (2 isolates) between August 2022 and May 2023, antimicrobial susceptibility testing (AST) was performed and gDNA was subjected to WGS. Analysis was performed to reveal the sequence types (ST), the relatedness to strains that caused other outbreaks and the arsenal of resistance genes harboured by these bacteria. Of 59 isolates, 85% were categorised as extensively drug-resistant (XDR), 13.6% as multidrug-resistant (MDR) and 1.7% as pan-drug-resistant. All isolates belonged to international clone (IC)2, of which the majority were of ST2 (91.5%). The isolates clustered well with those of a previous outbreak in the same hospital. In addition, isolates from hospitals in Lebanon clustered well together and some clustered with those originating from other countries. The observed genetic relatedness between the current isolates and those from the previous outbreaks underscores the importance of strict surveillance to limit the threat of outbreaks. Moreover, the clustering of isolates from Lebanon with others from distant countries proves the necessity to further investigate the international spread of drug-resistant pathogens and the implementation of control strategies.

In vitro and silico activity of piperlongumine against azole-susceptible/resistant Aspergillus fumigatus and terbinafine-susceptible/resistant Trichophyton species

In recent years, the widespread emergence of drug resistance in yeasts and filamentous fungi to existing antifungal armamentariums has become a severe threat to global health. There is also concern regarding increased rates of azole resistance in Aspergillus fumigatus and Terbinafine resistance in Trichophyton species. To overcome this concern of resistance to regular therapies, new antifungal drugs with novel and effective mechanisms are crucially needed. Herbal remedies may be promising strategies for the treatment of resistant infections. We aimed to investigate the in vitro and silico activity of piperlongumine against clinical azole susceptible/resistant A. fumigatus and terbinafine-susceptible/resistant Trichophyton species. In the current study, piperlongumine demonstrated potent antifungal activity, with minimum inhibitory concentrations (MICs) ranging from 0.016-4 μg/mL against Trichophyton isolates and 0.25-2 μg/mL for A. fumigatus isolates. Additionally, molecular docking studies indicated that piperlongumine has a strong binding affinity to the active sites of squalene epoxidase and sterol 14-alpha demethylase. However, further studies are warranted to correlate these findings with clinical outcomes and provide the basis for further investigations to pave the way for developing novel antifungal agents.

HGNN: A Hybrid Graph Neural Network Based on Transfer Learning for Linguistic Steganalysis

Steganography, especially in the form of text generation based on secret messages, has become a current research topic. It is more difficult to identify the hidden message when it embedded directly into the text without using a cover text, and it also has a higher embedding capacity. Owing to the high rate of imperceptibility and resistance to steganalysis of this type steganography, it is essential that steganalysis methods, generate better performance. Although the complexity of deep learning models increases the accuracy rate, it also increases the inference time. In this study, a linguistic steganalysis was performed with a lower inference time and a higher accuracy rate. In the developed model, first, differences between non-stega and steganographic texts were modelled by a finetuned Bert using the custom dataset. The disparity information obtained by fine-tuned model was distilled into 3 separate networks, BertGCN, BertGAT and BertGIN, for faster and more accurate inference. Then, these 3 distilled networks were combined through Transfer Learning to form a new model. Experiments demonstrates that the proposed model surpass other methods in terms of the accuracy (a success of 0.9879 at 3.22 bpw on text encoded through SAAC Encoding) and the effectiveness of inference (1.09 second).

Antibiotic prescribing intensity and community UTI resistance: a cross-sectional ecological study.

Antibiotic overuse is associated with antimicrobial resistance (AMR). It is unclear whether community AMR is driven by overall antibiotic use or by high levels of repeated (intense) use by individual patients. To determine the association between high antibiotic prescribing intensity (all antibiotic prescriptions; any indication), and rates of UTI resistance among patients within small communities. Repeated cross-sectional ecological analysis of geographical areas (population averaging 1500) from 2012-2015 using anonymised primary care data and urine cultures. For each area, we compared the percentage of antibiotic-prescribed patients who received≥5 prescriptions/3 years or≥4 prescriptions/year, with subsequent or same year UTI resistance rates. We also compared 'Average Daily Quantities' of all antibiotics prescribed, with UTI resistance rates, per year, per area. Results were adjusted for co-variates and analysed at area level using mixed effects logistic regression. Of 196,513 patients prescribed antibiotics in 69 areas, 16% were prescribed intensively (≥5 prescriptions in 3 years), receiving almost 30% of prescriptions. Of 12 308 confirmed UTI specimens (80% Escherichia Coli), 65% were resistant to at least one antibiotic (amoxicillin; cefalexin; ciprofloxacin; trimethoprim; nitrofurantoin). We found no significant association between high intensity 'any' antibiotic prescribing (same year/two preceding years) or overall 'any' antibiotic prescribing (same year) and UTI resistance. We found no relationship between concurrent high intensity 'any' antibiotic prescribing, and UTI resistance rates in small urban communities, pre-covid. Individual patient use of multiple antibiotics, even at high intensity, may not be an independent risk factor for community UTI resistance.

Development of Mg-3Al-0.5Zn-0.4Mn-1Gd Alloys as a Clavicle Bone Implant Material: A Literature Review

Abstract Magnesium alloys are widely used as implant materials such as Magnesium-Aluminium, Magnesium-Mangan, Magnesium-Zirconium, and others. These alloys still need further research regarding the mechanical properties of the alloy materials, resistance to corrosion rate, and anti-toxic properties to the human body. This article reviews the Magnesium alloy AZ31 (Magnesium-3Al-1Zn-0.4Mn) with the addition of the Gadolinium element as a candidate for the implant of the clavicle bone. The novelty of the proposed research is the change in composition in the form of a reduction of 0.5% Zn and the addition of 1% Gd. Furthermore, anodizing and coating treatment is implemented to improve the mechanical stability of the alloy. This alloy is supposed to improve the physical, mechanical, and chemical properties of magnesium. The addition of gadolinium can increase the mechanical strength, creep resistance, and rate of corrosion resistance.

A One Health exploration of antimicrobial resistance in Escherichia coli originated from urban and rural lakes ecosystem.

Antimicrobial resistance (AMR) has become one of the most serious threats to One Health. Aquatic environments are an ideal non-clinical AMR reservoir and can act as a key battlefront for tackling the AMR. However, AMR data using the One Health approach remain scarce in aquatic environments worldwide. Here, we extensively assessed AMR in Escherichia coli isolated from urban and rural lake ecosystems using the One Health perspective. A total of 162 E. coli isolates obtained from lakes were tested against 25 antimicrobials using an in-vitro antimicrobial susceptibility testing method. A low (2%) to moderate (45%) drug resistance rate was found for all antimicrobials used in human/veterinary medicine or animal/plant agriculture. However, <80% E. coli isolates exhibited multidrug resistance (MDR) phenotype to highly important (amikacin, gentamicin, trimethoprim) or critically important (amoxicillin, ampicillin, colistin) drugs of both human and veterinary medicine. Of concern, >50% of E. coli isolates exhibited MDR to drugs used as last-resorts (chloramphenicol, colistin) or as frontline (nitrofurantoin, sulfamethoxazole, ampicillin, gentamicin) against E. coli infections. In conclusion, the presence of MDR E. coli strains in urban or rural lake ecosystems highlights their possible role as AMR reservoirs with potential One Health risks.

Surface etching-reconstruction effectively suppresses icing in jet fuel pipeline

In extreme weather, icing in aircraft fuel systems poses a serious threat to flight safety. Moisture in fuel can freeze inside pipes at high altitudes, risking engine operation and performance. This study explores the use of superhydrophobic technology to prevent icing. Aerospace-grade aluminum alloy (6061) was chemically etched with FeCl3 to create rough micro and nano structures. The surface was then modified with low surface energy perfluoropolyether (PFPE) to form a superhydrophobic coating. Tests showed that a 1.0 wt% PFPE coating exhibited excellent superhydrophobic and oleophobic properties, with a water contact angle of 154.79° and a jet fuel (RP-3) contact angle of 150.13°. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) analyses confirmed the presence of C-F3 and C-F2 bonds. The electrochemical corrosion resistance test shows that the coating has good corrosion resistance and the corrosion resistance rate is 0.61 mm/a. The coating also demonstrated outstanding waterproof performance, resisting grease and stain adhesion under jet fuel immersion. This approach offers a promising solution for surface protection and functional material design. Future research will further optimize its performance and explore broader applications.

Understanding the Evolution and Transmission Dynamics of Antibiotic Resistance Genes: A Comprehensive Review.

Antibiotic resistance poses a formidable challenge to global public health, necessitating comprehensive understanding and strategic interventions. This review explores the evolution and transmission dynamics of antibiotic resistance genes, with a focus on Bangladesh. The indiscriminate use of antibiotics, compounded by substandard formulations and clinical misdiagnosis, fuels the emergence and spread of resistance in the country. Studies reveal high resistance rates among common pathogens, emphasizing the urgent need for targeted interventions and rational antibiotic use. Molecular assessments uncover a diverse array of antibiotic resistance genes in environmental reservoirs, highlighting the complex interplay between human activities and resistance dissemination. Horizontal gene transfer mechanisms, particularly plasmid-mediated conjugation, facilitate the exchange of resistance determinants among bacterial populations, driving the evolution of multidrug-resistant strains. The review discusses clinical implications, emphasizing the interconnectedness of environmental and clinical settings in resistance dynamics. Furthermore, bioinformatic and experimental evidence elucidates novel mechanisms of resistance gene transfer, underscoring the dynamic nature of resistance evolution. In conclusion, combating antibiotic resistance requires a multifaceted approach, integrating surveillance, stewardship, and innovative research to preserve the efficacy of antimicrobial agents and safeguard public health.

Clinical characteristics and prognosis of bloodstream infections with carbapenem-resistant Gram-negative organisms in patients with hematological malignancies: a multicenter case-control study in China

ObjectiveTo investigate clinical characteristics of hematological malignancy (HM) patients with carbapenem-resistant gram-negative organism (CRO) bloodstream infections (BSI) in China, and to elucidate the prognostic risk factors of CRO BSI. MethodsWe conducted a multicenter case-control study of 201 HM patients with CRO BSI between 2018-2020. Antimicrobial susceptibility testing and whole genome sequencing were performed for CRO isolates. Independent risk factors for 28-day crude mortality of were analyzed using Cox proportional hazards regression models. The subgroups of major species were also evaluated. ResultsThe pathogens responsible for CRO BSI in HM patients dominated by ST11 CRKP, ST167 CREC and ST463 CRPA. Most isolates produced carbapenemases with KPC and NDM being the main. CRO isolates had resistance rates to conventional antimicrobials ranging from 55%-100% and poor susceptibility to novel antimicrobials related to carbapenemases and species. The 28-day crude mortality was 24.2%. Non-Hodgkin lymphoma, heart disease, blaKPC-2 positive, empirical antibiotic therapy with linezolid, Pitt bacteremia score >3.5 were risk factors for 28-day mortality and appropriate definitive antibiotic therapy, tigecycline-containing therapy and aminoglycoside-containing therapy were protective factors. blaKPC-2 positive in CRKP and ST463 in CRPA were associated with Pitt bacteremia score > 3.5. Solid tumor and other site infections before BSI were risk factors for ST463 CRPA BSI and Pulmonary infection before BSI was risk factor for KPC-KP BSI. ConclusionsThe antimicrobial resistance of CRO isolates for BSI in HM patients is critical. HM patients with CRO BSI should be treated with appropriate definitive antibiotic therapy based on early clarification of pathology and their antimicrobial susceptibility.

Pretreatment drug resistance among people living with HIV from 2018 to 2022 in Guangzhou, China.

The presence of pretreatment drug resistance (PDR) is posing an increasing threat to HIV control. Here we investigated drug resistance mutations (DRMs) and PDR among 6831 HIV-infected individuals from 2018 to 2022 in Guangzhou, China. DRMs were detected among 24.5% of the patients. The overall prevalence of PDR was 7.4%, with resistance rate to nucleotide reverse transcriptase inhibitor (NRTI) being 1.3%, nonnucleoside reverse transcriptase inhibitor (NNRTI) 4.8%, and protease inhibitor (PI) 1.4%. Abacavir (0.8%) resistance was the most common in NRTI, followed by resistance to emtricitabine (0.6%), lamivudine (0.6%), and tenofovir disoproxil fumarate (0.3%). In NNRTI, nevirapine (3.7%) resistance was the most common, followed by efavirenz (3.5%) and rilpivirine (3.4%). Among PI, resistance to tipranavir (0.8%), nelfinavir (0.6%), fosamprenavir (0.2%) and lopinavir (0.1%) was most frequent. Annual prevalence of PDR showed an increase trend from 2018 to 2022, although not significant. In the multivariable logistic regression model, hepatitis B surface antigen positivity, circulating recombinant form (CRF) 55_01B, CRF08_BC, CRF59_01B, and subtype B were demonstrated as associated risk factors for PDR. The overall prevalence of PDR in Guangzhou was moderate, with relatively severe NNRTI resistance. Therefore, it remains crucial to continue monitoring PDR among newly diagnosed HIV-infected individuals.

Isoniazid resistance pattern among pulmonary tuberculosis patients in Bangladesh: An exploratory study

ObjectivesIn high tuberculosis (TB) burden countries such as Bangladesh, research and policy tend to focus on rifampicin (RIF)-resistant TB patients, leaving RIF-sensitive but isoniazid (INH)-resistant (Hr-TB) patients undiagnosed. Our study aims to determine the prevalence of INH resistance among pulmonary TB patients in selected health care facilities in Bangladesh. MethodsThis study was conducted across nine TB Screening and Treatment Centres situated in Bangladesh. Sputum samples from 1084 Xpert-positive pulmonary TB patients were collected between April 2021 and December 2022 and cultured for drug susceptibility testing. Demographic and clinical characteristics of Hr-TB and drug-susceptible TB patients were compared. ResultsAmong available drug susceptibility testing results of 998 culture-positive isolates, the resistance rate of any INH regardless of RIF susceptibility was 6.4% (64/998, 95% CI: 4.9–8.2). The rate was significantly higher in previously treated (21.1%, 16/76, 95% CI: 12.0–34.2) compared with newly diagnosed TB patients (5.2%, 48/922, 95% CI: 3.8–6.9) (p < 0.001). The rate of Hr-TB was 4.5% (45/998, 95% CI: 3.3–6.0), which was also higher among previously treated patients (6.6%, 5/76, 95% CI: 1.4–13.5) compared with newly diagnosed TB patients (4.3%; 40/922, 95% CI: 3.1–5.9) (p 0.350). Most importantly, the rate of Hr-TB was more than double compared with MDR-TB (4.5%, 45/998, vs. 1.9%, 19/998) found in the current study. DiscussionThis study reveals a high prevalence of Hr-TB, surpassing even that of the multi-drug-resistant TB in Bangladesh. This emphasizes the urgent need to adopt WHO-recommended molecular tools at the national level for rapid detection of INH resistance so that patients receive timely and appropriate treatment.

Molecular Characterization of Multidrug-Resistant Escherichia coli from Fecal Samples of Wild Animals.

Antimicrobial resistance (AMR) surveillance in fecal Escherichia coli isolates from wildlife is crucial for monitoring the spread of this microorganism in the environment and for developing effective AMR control strategies. Wildlife can act as carriers of AMR bacteria and spread them to other wildlife, domestic animals, and humans; thus, they have public health implications. A total of 128 Escherichia coli isolates were obtained from 66 of 217 fecal samples obtained from different wild animals using media without antibiotic supplementation. Antibiograms were performed for 17 antibiotics to determine the phenotypic resistance profile in these isolates. Extended-spectrum β-lactamase (ESBL) production was tested using the double-disc synergy test, and 29 E. coli strains were selected for whole genome sequencing. In total, 22.1% of the wild animals tested carried multidrug-resistant E. coli isolates, and 0.93% (2/217) of these wild animals carried E. coli isolates with ESBL-encoding genes (blaCTX-M-65, blaCTX-M-55, and blaEC-1982). The E. coli isolates showed the highest resistance rates to ampicillin and were fully susceptible to amikacin, meropenem, ertapenem, and imipenem. Multiple resistance and virulence genes were detected, as well as different plasmids. The relatively high frequency of multidrug-resistant E. coli isolates in wildlife, with some of them being ESBL producers, raises some concern regarding the potential transmission of antibiotic-resistant bacteria among these animals. Gaining insights into antibiotic resistance patterns in wildlife can be vital in shaping conservation initiatives and developing effective strategies for responsible antibiotic use.

Distribution characteristics of integrons and correlation analysis of antibiotic resistance in urine isolated Enterobacter cloacae.

This study aims to understand the distribution of integrons among Enterobacter cloacae isolated from clinical urine specimens in our hospital, as well as the molecular characteristics of the variable region resistance gene cassette of integron-positive strains and its relationship with drug resistance. We collected a total of 80 strains of Enterobacter cloacae isolated from urine specimens of hospitalized patients in our hospital between August 2019 and July 2023, and conducted drug sensitivity testing on them. Polymerase Chain Reaction (PCR) technology was employed to screen these strains for Class 1, 2, and 3 integrons. Following this, the promoter and variable regions of integron-positive strains were amplified and sequenced. Additionally, Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) was utilized for homology analysis of integron-positive strains. Among the 80 clinical strains, Class 1 integrons were detected in 31 (38.8%) strains, and the following resistance gene cassettes were identified: aadA2, aadA1, aadB, aac(6'), and catB8. Three types of variable region promoters were observed: PcS (4 strains), PcW (7 strains), and PcH1 (17 strains), with consistently inactive downstream P2 promoters. Additionally, Class 2 integrons were detected in 5 (6.3%) strains, carrying the variable region resistance gene cassette dfrA1-sat2-aadA1. The promoters for Class 2 integrons were uniformly of the Pc2D-Pc2A-Pc2B-Pc2C type. No Class 3 integrons were detected. The strains containing integrons showed significantly higher resistance rates to ciprofloxacin, compound sulfamethoxazole, levofloxacin, gentamicin, amikacin, and tobramycin compared to those without integrons (P<0.05). 35 strains of Enterobacter cloacae carrying integrons are primarily classified into three genotypes: A, B, and C. These genotypes are mainly distributed in the urology department and Intensive Care Unit (ICU). The distribution of variable region gene boxes and promoter types is relatively concentrated in the same genotype. Our study confirmed that Enterobacter cloacae isolated from urine samples predominantly carries Class 1 integrons with an extended array of antibiotic-resistant genes. For future research, it is recommended to explore additional resistance mechanisms and evaluate the effectiveness of new therapeutic strategies. Clinicians should be vigilant about the possibility of clonal dissemination and implement enhanced infection control measures in hospital settings.

Prevalence and antimicrobial resistance of Pseudomonas aeruginosa in food in Ho Chi Minh City

Pseudomonas aeruginosa is a bacterium that commonly found in various environments, including food, soil, and water. The significant concern is it&amp;rsquo;s resistance to many antimicrobial agents and it&amp;rsquo;s role in the spread of antibiotic resistance genes. This study investigated P. aeruginosa contamination in food products in Ho Chi Minh City and found the following contamination rates: pork (44.8%; 13/29), beef (38.5%; 10/26), fish (30.0%; 9/30), chicken (25.9%; 7/27), street drinks (25.9%; 7/27), shrimp (17.9%; 5/28), raw milk (10.7%; 3/28). The highest average quantity of P. aeruginosa contamination was observed in beef samples, with over 104 CFU/g, while shrimp samples had the lowest, nearly 103 CFU/g. Among the 94 isolates examined, 63 were sensitive or showed intermediate resistance to ten antimicrobial agents. Resistance was observed in 32 isolates, with the hightest resistance rates to aztreonam (28.9%), followed by ciprofloxacin (11.7%), and gentamicin (2.1%). The antimicrobial resistance rates of P. aeruginosa isolates varied by food type: pork (27.6%), fish (16.7%), shrimp (10.7%), chicken (7.4%), street drinks (7.4%), and beef (3.9%). All P. aeruginosa isolates from raw milk were sensitive to the tested antimicrobials. The findings suggest a need for stricter regulations to control P. aeruginosa contamination in food products. Further research is also recommended to explore the potential for transmission of drug resistance genes from P. aeruginosa in contaminated food.

Choice of Empirical Treatment in Patients With Wound Infection

Objective: We aimed to determine the distribution of infectious agents in wound culture specimens, their resistance rates, and to evaluate empirical treatment choices in wound infections. Methods: Wound culture results of adult patients between 2016-2020 were retrospectively investigated. Determination of bacteria and antibiotic sensitivity tests were done using conventional methods and automatized systems. Results: A total of 2576 wound specimens were sent, and significant bacterial growth was detected in 1254 (48.7%). Most frequently isolated agent was Escherichia coli (E.coli) (24.2%), followed by Staphylococcus aureus (S.aureus) (16.8%). The highest rate of resistance in Enterobacterales species was against amoxicillin-clavulanate (AMC), except Proteus mirabilis. Antibiotics that Enterobacterales species were most sensitive were amikacin and carbapenems, while it was trimethoprim – sulfamethoxazole (TMP-SXT) for Acinetobacter baumannii, and amikacin for Pseudomonas aeruginosa. The highest rate of resistance in S.aureus strains was against penicillin, with a methicillin resistance rate of 22.9%, while no resistance was found against vancomycin. Conclusion: Initial treatment in wound infections is empirical, and the range of treatment is narrowed when results of culture and sensitivity tests are obtained. Clindamycin, AMC, TMP – SXT and ciprofloxacin seem to be appropriate for outpatients, while TMP-SXT or vancomycin for gram-positive cocci, and TMP-SXT and amikacin combination for gram – negatives, and carbapenems as a last resort.