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1.
Protein Expr Purif ; 225: 106583, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39168394

RESUMEN

In recombinant protein purification, differences in isoelectric point (pI)/surface charge and hydrophobicity between the product and byproducts generally form the basis for separation. For bispecific antibodies (bsAbs), in many cases the physicochemical difference between product and byproducts is subtle, making byproduct removal considerably challenging. In a previous report, with a bsAb case study, we showed that partition coefficient (Kp) screening for the product and byproducts under various conditions facilitated finding conditions under which effective separation of two difficult-to-remove byproducts was achieved by anion exchange (AEX) chromatography. In the current work, as a follow-up study, we demonstrated that the same approach enabled identification of conditions allowing equally good byproduct removal by mixed-mode chromatography with remarkably improved yield. Results from the current and previous studies proved that separation factor determination based on Kp screening for product and byproduct is an effective approach for finding conditions enabling efficient and maximum byproduct removal, especially in challenging cases.


Asunto(s)
Anticuerpos Biespecíficos , Proteínas Recombinantes , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Cromatografía por Intercambio Iónico/métodos , Humanos
2.
Cureus ; 16(8): e66057, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39224723

RESUMEN

BACKGROUND:  Following the emergence of the JN.1 SARS-CoV-2 variant, variants with key mutations in the spike protein, such as L455F, F456L, and R346T, were identified. In early January 2024, the KP.2 (JN.1.11.1.2) variant was first identified in clinical samples. Its increasing global prevalence has raised concerns over its transmission and clinical impact. The study investigates KP.2*'s (*indicates KP.2 and all its sub-lineages) spread and clinical severity in Maharashtra. METHODS:  This study involved 5,173 Indian SARS-CoV-2 whole genome sequences with collection dates between November 1, 2023 and June 24, 2024. Lineage analysis of sequences was performed using Nextclade software (version 3.8.0). Telephonic interviews were conducted to confirm the demographic details and obtain clinical information on the KP.2* cases. The obtained data were recorded and analyzed using Microsoft® Excel (Microsoft Corporation, Redmond, WA). RESULTS:  Among the 5,173 sequences analyzed, JN.1* appeared as the predominant lineage (65.96%, 3412/5173), followed by KP.2* (7.83%, 405/5173) and KP.1* (3.27%, 169/5173). In India, KP.2* was first detected on December 2, 2023, in Odisha. The majority of KP.2* sequences were from Maharashtra (248/405, 61.23%), followed by West Bengal (38/405, 9.38%), Gujarat (27/405, 6.67%), and Rajasthan (24/405, 5.93%). Maharashtra reported its first KP.2* sequences on January 24, 2024. The clinical study included 160 cases of the KP.2* variant from Maharashtra. Of these, 95.63% (153/160) presented with mild symptoms, such as fever (108/160, 67.50%), cold (87/160, 54.38%), cough (80/160, 50%), sore throat (44/160, 27.5%), body ache (43/160, 26.88%), and fatigue (42/160, 26.25%). About 33.13% (53/160) of the cases required institutional quarantine or hospitalization, with the rest managed at home. Among those hospitalized, 50.94% (27/53) received conservative treatment, while 49.06% (26/53) needed supplemental oxygen, steroids, or antiviral therapy. Regarding the vaccination status, 89.38% (143/160) of the cases had received at least one dose of the COVID-19 vaccine, whereas 10% (16/160) were unvaccinated, with the majority of the unvaccinated being children aged zero to nine years (7/16, 43.75%). The overall recovery rate for KP.2* cases was 99.38% (159/160), with only 0.62% (1/160) succumbing to the disease. CONCLUSION:  The KP.2 variant has become the dominant SARS-CoV-2 variant in India and Maharashtra. Despite the affected individuals experiencing mild symptoms, studies have shown lower neutralization titers and high infectivity due to FLiRT mutations, suggesting KP.2's potential rise to global dominance.

3.
Cureus ; 16(7): e65796, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39219944

RESUMEN

PURPOSE: The study aimed to compare the results of colistin-susceptibility testing performed using the automated VITEK system, colistin broth microdilution (BMD), and colistin broth disk elution (CBDE) methods. MATERIALS AND METHODS: This exploratory study was conducted in a tertiary care center in South India. Carbapenem-resistant Klebsiella pneumoniae (n = 49) isolates collected from a clinical microbiology laboratory over six months (March-September 2023) were used for the study. RESULTS: Among the 49 carbapenem-resistant Klebsiella pneumoniae isolates, 42 were found to be susceptible to carbapenem by all three methods. Seven isolates were found to be resistant to colistin using BMD and CBDE methods. Two isolates were incorrectly detected as colistin-susceptible, and one isolate was wrongly categorized as colistin-resistant using the automated VITEK system. CONCLUSION:  CBDE is a reliable and cost-effective method that can be adopted in the routine microbiology laboratory for colistin-susceptibility testing, as it does not require any specialized equipment or techniques and is 100% consistent with the gold standard BMD method. Although the automated VITEK system is used in most routine microbiological laboratories for antibiotic-susceptibility testing, it cannot be reliably used for colistin-susceptibility testing due to its high error rates (very major error rate of 28.5%; major error rate of 2.4%).

4.
J Ethnopharmacol ; : 118795, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278293

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese Medicine (TCM) has a rich history spanning 2,000 years. Shuanghuanglian, a traditional Chinese herbal formula composed of three botanicals, is primarily used to treat colds, respiratory infections (including bacterial pneumonia), and pharyngitis. Previous research has found that the volatile oil of Shuanghuanglian is crucial for its efficacy. However, there is a lack of studies investigating its mechanisms. AIM OF THE STUDY: This study aims to explore the antibacterial and anti-inflammatory mechanisms of Shuanghuanglian volatile oil and its potential to enhance the antibacterial effects when used in conjunction with antibiotics. METHODS: Determination of the GC-MS fingerprint of SVO using Gas Chromatography-Mass Spectrometry (GC-MS) , The antibacterial effects of SVO on multidrug-resistant Klebsiella pneumoniae (MDR-KP) were assessed by detecting MIC, checkerboard method assay, time-kill curves, resistance growth curves, transcriptome sequencing analysis, scanning electron microscopy(SEM), purification, and quantitative analysis of extracellular polysaccharides(EPS). In vivo part, an MDR-KP induced mouse pneumonia model was established to evaluate the mitigating effects of SVO on mouse pneumonia, using comprehensive network pharmacology and bioinformatics to identify genes related to bacterial pneumonia and potential targets of SVO. Validation was performed through molecular docking, qPCR, and ELISA tests. RESULTS: SVO modulates the expression of MDR-KP mRNA for wecB, wecC, murA, murD, murE, murF, inhibiting the synthesis of O-antigen polysaccharides and peptidoglycans, thereby compromising bacterial cell wall integrity and affecting the synthesis of biofilms. These actions not only exhibit antibacterial effects but also enhance antibacterial activity, restoring the sensitivity of CEF to MDR-KP. SVO suppresses the biological activity of PTGS2, reducing the production of Prostaglandin E2 (PGE2), thereby exerting antipyretic and anti-inflammatory effects, providing new insights for the development of natural non-steroidal anti-inflammatory drugs (NSAIDs). CONCLUSIONS: Our research indicates that SVO exerts antipyretic, anti-inflammatory, and antibacterial synergistic effects through multiple pathways.

5.
Emerg Microbes Infect ; 13(1): 2402880, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39259045

RESUMEN

The recently dominant SARS-CoV-2 Omicron JN.1 has evolved into multiple sublineages, with recurrent spike mutations R346T, F456L, and T572I, some of which exhibit growth advantages, such as KP.2 and KP.3. We investigated these mutations in JN.1, examining their individual and combined effects on immune evasion, ACE2 receptor affinity, and in vitro infectivity. F456L increased resistance to neutralization by human sera, including those after JN.1 breakthrough infections, and by RBD class-1 monoclonal antibodies, significantly altering JN.1 antigenicity. R346T enhanced ACE2-binding affinity and modestly boosted the infectivity of JN.1 pseudovirus, without a discernible effect on serum neutralization, while T572I slightly bolstered evasion of SD1-directed mAbs against JN.1's ancestor, BA.2, possibly by altering SD1 conformation. Importantly, expanding sublineages such as KP.2 containing R346T, F456L, and V1104L, showed similar neutralization resistance as JN.1 with R346T and F456L, suggesting V1104L does not appreciably affect antibody evasion. Furthermore, the hallmark mutation Q493E in KP.3 significantly reduced ACE2-binding affinity and viral infectivity, without noticeably impacting serum neutralization. Our findings illustrate how certain JN.1 mutations confer growth advantages in the population and could inform the design of the next COVID-19 vaccine booster.


Asunto(s)
COVID-19 , Evasión Inmune , Mutación , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Humanos , SARS-CoV-2/genética , SARS-CoV-2/inmunología , COVID-19/virología , COVID-19/inmunología , Anticuerpos Neutralizantes/inmunología , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Monoclonales/inmunología
6.
Cureus ; 16(7): e63976, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39109109

RESUMEN

This systematic review aimed to consolidate findings on the etiology of community-acquired pneumonia (CAP) among Indian adults. We adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Guidelines 2020 and conducted a comprehensive search across databases including PubMed, Scopus-Elsevier, and hand-searched reference lists using key terms such as "Community-Acquired Pneumonia," "CAP," "Indian," and "adults." Articles published between January 2010 and January 2024 were included, with exclusions for studies involving pediatric populations, non-Indian patients, or those published before 2010. From an initial pool of 344 articles, duplicates were removed and titles and abstracts were screened, resulting in nine studies meeting the inclusion criteria. The analysis of pooled data comprising 1,643 Indian adult participants revealed the following pathogen distribution: Streptococcus pneumoniae was the most common organism, accounting for 33% of the cases. This was followed by Klebsiella pneumoniae at 23%, Staphylococcus aureus at 10%, Mycoplasma pneumoniae and Legionella pneumophila each at 7%, and Chlamydia pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa each at 4%. Notably, the review highlights a rising incidence of K. pneumoniae in CAP cases, which is a significant concern and should be considered when treating CAP patients in India. The findings emphasize the importance of comprehensive diagnostic testing, including advanced methods such as bronchoalveolar lavage, urinary antigen tests, serology for atypical pathogens, and enzyme-linked immunosorbent assays, to improve diagnostic yield and guide targeted antibiotic therapy. This review underscores the need for updated empirical treatment guidelines that account for dominant pathogens. Future research should focus on employing advanced diagnostic methods to enhance understanding of CAP etiology.

7.
Front Cell Infect Microbiol ; 14: 1408179, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39119288

RESUMEN

Introduction: Hypervirulent Klebsiella pneumoniae (hvKp) and carbapenem-resistant K. pneumoniae (CR-Kp) are rapidly emerging as opportunistic pathogens that have a global impact leading to a significant increase in mortality rates among clinical patients. Anti-virulence strategies that target bacterial behavior, such as adhesion and biofilm formation, have been proposed as alternatives to biocidal antibiotic treatments to reduce the rapid emergence of bacterial resistance. The main objective of this study was to examine the efficacy of fatty acid-enriched extract (AWME3) derived from the fat of Black Soldier Fly larvae (Hermetia illucens) in fighting against biofilms of multi-drug resistant (MDR) and highly virulent Klebsiella pneumoniae (hvKp) pathogens. Additionally, the study also aimed to investigate the potential mechanisms underlying this effect. Methods: Crystal violet (CV) and ethidium bromide (EtBr) assays show how AWME3 affects the formation of mixed and mature biofilms by the KP ATCC BAA-2473, KPi1627, and KPM9 strains. AWME3 has shown exceptional efficacy in combating the hypermucoviscosity (HMV) virulent factors of KPi1627 and KPM9 strains when tested using the string assay. The rudimentary motility of MDR KPM9 and KP ATCC BAA-2473 strains was detected through swimming, swarming, and twitching assays. The cell wall membrane disturbances induced by AWME3 were detected by light and scanning electron microscopy and further validated by an increase in the bacterial cell wall permeability and Lewis acid-base/van der Waals characteristics of K. pneumoniae strains tested by MATS (microbial adhesion to solvents) method. Results: After being exposed to 0.5 MIC (0.125 mg/ml) of AWME3, a significant reduction in the rudimentary motility of MDR KPM9 and KP ATCC BAA-2473 strains, whereas the treated bacterial strains exhibited motility between 4.23 ± 0.25 and 4.47 ± 0.25 mm, while the non-treated control groups showed significantly higher motility ranging from 8.5 ± 0.5 to 10.5 ± 0.5 mm. Conclusion: In conclusion, this study demonstrates the exceptional capability of the natural AWME3 extract enriched with a unique combination of fatty acids to effectively eliminate the biofilms formed by the highly drug-resistant and highly virulent K. pneumoniae (hvKp) pathogens. Our results highlight the opportunity to control and minimize the rapid emergence of bacterial resistance through the treatment using AWME3 of biofilm-associated infections caused by hvKp and CRKp pathogens.


Asunto(s)
Antibacterianos , Biopelículas , Dípteros , Farmacorresistencia Bacteriana Múltiple , Ácidos Grasos , Klebsiella pneumoniae , Larva , Factores de Virulencia , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Animales , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/patogenicidad , Ácidos Grasos/metabolismo , Factores de Virulencia/metabolismo , Dípteros/microbiología , Larva/microbiología , Larva/efectos de los fármacos , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Virulencia/efectos de los fármacos , Infecciones por Klebsiella/microbiología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo
9.
Front Cell Infect Microbiol ; 14: 1411658, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39165917

RESUMEN

Objective: This study used whole-genome sequencing (WGS) to explore the genetic diversity, virulence factors, and antimicrobial resistance determinants of string test-positive Klebsiella pneumoniae (KP) over a 4-year surveillance period in Huzhou, China. Methods: In total, 632 clinical isolates were collected via hospital surveillance from 2020 to 2023; 100 were positive in the string test and these 100 strains were subjected to antimicrobial susceptibility testing using an agar dilution method followed by WGS. Results: The resistance rates to cefotaxime (77.0%), trimethoprim-sulfamethoxazole (67.0%), and nalidixic acid (64.0%) were high. Multilocus sequence typing revealed high genetic diversity; there were 33 sequence types (STs) and 15 capsular serotypes. The most common ST was ST23 (16.0%) and the most common capsular serotype was K1 (22.5%). Virulome analysis revealed among-strain differences in virulence factors that affected bacterial adherence, efflux pump action, iron uptake, nutritional factors, metabolic regulation, the secretion system, and toxin production. The Kleborate strain-specific virulence scores of all 100 string test-positive KPs were derived: 28 strains scored 5, 28 scored 4, 21 scored 3, 12 scored 1, and 11 scored 0. All 77 strains with scores of 3 to 5 contained the iucA gene. The phylogeny based on whole-genome single nucleotide polymorphisms (wgSNPs) indicated high clonality; the string test-positive KP strains were grouped into six clades. Closely related isolates in each genetic cluster usually shared STs. Conclusion: The present study highlights the significance of the KP iucA gene in terms of hypervirulence and the diverse genotypes of string test-positive KP strains isolated in Huzhou hospitals.


Asunto(s)
Infecciones por Klebsiella , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Factores de Virulencia , Secuenciación Completa del Genoma , China/epidemiología , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/clasificación , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Factores de Virulencia/genética , Variación Genética , Antibacterianos/farmacología , Serogrupo , Filogenia , Genoma Bacteriano , Farmacorresistencia Bacteriana/genética , Virulencia/genética , Masculino , Femenino
10.
J Med Virol ; 96(8): e29877, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39169721

RESUMEN

Emerging evidence shows increased humoral response post-omicron surge, but research on T cell responses is limited. This study investigated the durability, magnitude, and breadth of SARS-CoV-2-spike-specific T cell responses in 216 two-dose vaccinated individuals pre- and post-omicron surge. Post-surge samples showed enhanced T cell responses, indicating widespread asymptomatic exposure to omicron. Further analysis of 105 individuals with multiple exposures to SARS-CoV-2 through boosters or infections showed that post-omicron, two-dose vaccinated individuals had T cell responses comparable to those of COVID-19 convalescents or boosted individuals. Additionally, we report cross-reactive T cell responses against omicron sub-variants, including BA2.86, remained strong, with preserved frequencies of spike-specific stem-cell-like memory T cells. In silico prediction indicates that mutated epitopes of JN.1 and KP.2 retain over 95.6% of their HLA binding capability. Overall, our data suggests that T cell responses are sustained, enhanced, and cross-reactive against emerging SARS-CoV-2 variants following symptomatic or asymptomatic omicron infection.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Reacciones Cruzadas , Epítopos de Linfocito T , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Linfocitos T , Humanos , COVID-19/inmunología , SARS-CoV-2/inmunología , Reacciones Cruzadas/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Linfocitos T/inmunología , Vacunas contra la COVID-19/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Masculino , Persona de Mediana Edad , Adulto , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Adulto Joven
11.
Cureus ; 16(7): e64339, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39130980

RESUMEN

Pneumopericardium due to bronchopericardial fistula formation is a rare complication secondary to necrotizing pneumonia. Several such cases are reported due to different suppurative bacterial infections. Persistent fistulous communication has been reported to lead to tension pneumopericardium and hemodynamic instability, requiring urgent intervention such as pericardial drainage. A 41-year-old male patient, known to have chronic kidney disease and diabetes mellitus, presented with acute respiratory symptoms. Upon admission, the patient was febrile and required oxygen support via nasal prongs. A chest X-ray showed fibrocavitatory changes on the right side, with patchy air shadowing around the cardiac silhouette and a continuous diaphragm sign. A contrast-enhanced computed tomography (CECT) thorax revealed extensive areas of consolidation with necrotic areas within, forming a thin-walled cavity involving the right middle lobe. Also, suspicious communication of this cavity with the pericardial cavity along the right atrium was seen, with minimal pericardial collection and air foci within. The pleural fluid culture showed growth of Klebsiella pneumoniae. According to the antibiotic sensitivity report, the patient was started on IV meropenem and gentamicin for 21 days while monitoring kidney functions. The patient clinically improved on antibiotics, and follow-up radiological investigations showed resolution of pneumopericardium. In this patient, pneumopericardium was mild, and there was no evidence of tension pneumopericardium. Thus, conservative management with antibiotics was provided, with successful resolution. Unlike this case, if evidence of tension pneumopericardium had been present, emergency interventions for decompression would have been required, and these cases would have had a poor prognosis. This case demonstrates the importance of high suspicion and early diagnosis of pneumopericardium in patients with necrotizing pneumonia. Prompt treatment in these patients can prevent further life-threatening sequelae.

12.
Sci Rep ; 14(1): 15865, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38982103

RESUMEN

The study of the Kadomtsev-Petviashvili (KP) model is widely used for simulating several scientific phenomena, including the evolution of water wave surfaces, the processes of soliton diffusion, and the electromagnetic field of transmission. In current study, we explore some multiple soliton solutions of the (3+1)-dimensional generalized KP model via applying modified Sardar sub-equation approach (MSSEA). By extracting the novel soliton solutions, we can effectively obtain singular, dark, combo, periodic and plane wave solutions through a multiple physical regions. We also investigate the chaotic structure of governing model using the chaos theory. The behavior of the collected solutions is visually depicted to demonstrate the physical properties of the proposed model. The solutions obtained in this paper can expand the existing solutions of the (3+1)-dimensional KP model and enhance our understanding of the nonlinear dynamic behaviors. This approach allows for consistent and effective treatment of the computation process for nonlinear KP model.

13.
Cureus ; 16(6): e63132, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39055465

RESUMEN

BACKGROUND:  Community-acquired pneumonia (CAP) is an acute lung infection affecting the alveoli in individuals who have not had recent exposure to healthcare settings. It is characterized by newly detected pulmonary infiltration on a chest X-ray or computed tomography scan, accompanied by at least two of the following symptoms: a new or worsening cough, shortness of breath, increased sputum production, fever or hypothermia, pleuritic chest pain, hypoxia, confusion, or an abnormal WBC count (either leukopenia or leukocytosis). It is a major contributor to global mortality and morbidity, especially in elderly populations. This study aims to investigate the etiology of CAP in our region and analyze the clinical characteristics of patients diagnosed with CAP. METHODOLOGY:  This prospective, hospital-based study was conducted at Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, a 2,011-bed multispecialty hospital. The study included 100 patients over 18 years old, diagnosed with CAP, and hospitalized between January 2023 and January 2024. All patients underwent a thorough clinical assessment, and sputum cultures were collected on the day of admission. Patients under 18 years old, those who had been hospitalized within the preceding two weeks, individuals with pneumonia caused by tuberculosis or aspiration pneumonia, patients with compromised immune systems, and pregnant women were excluded. RESULTS:  The study included 100 patients with a mean age of 53.13 years (±18.31). The most common age group was 59-68 years, which included 25 (25%) cases, followed by the 69-78 year age group with 18 (18%) cases and the 18-28 year age group with 15 (15%) cases. The majority were male, with 61 (61%) cases. Common symptoms included fever in 78 cases (78%), chest pain in 69 cases (69%), dyspnea in 65 cases (65%), and cough in 51 cases (51%). Sputum cultures showed growth in 65 cases (65%), with Klebsiella pneumoniae being the most prevalent pathogen in 28 cases (43%), followed by Streptococcus pneumoniae in 18 cases (28%). Together, these two pathogens accounted for 46 out of 65 positive samples (70%). CONCLUSIONS:  This study highlights the clinical profile and rising etiology of K. pneumoniae in CAP in adults in Western India, particularly in the elderly. These findings underscore the need for periodic updates on CAP etiology to inform empirical treatment strategies effectively. Future research should use advanced diagnostics and diverse samples to refine CAP management, with continuous monitoring to update treatment protocols.

14.
Antimicrob Resist Infect Control ; 13(1): 70, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961463

RESUMEN

OBJECTIVES: Genomic surveillance of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is crucial for virulence, drug-resistance monitoring, and outbreak containment. METHODS: Genomic analysis on 87 KPC-Kp strains isolated from 3 Northern Italy hospitals in 2019-2021 was performed by whole genome sequencing (WGS), to characterize resistome, virulome, and mobilome, and to assess potential associations with phenotype resistance and clinical presentation. Maximum Likelihood and Minimum Spanning Trees were used to determine strain correlations and identify potential transmission clusters. RESULTS: Overall, 15 different STs were found; the predominant ones included ST307 (35, 40.2%), ST512/1519 (15, 17.2%), ST20 (12, 13.8%), and ST101 (7, 8.1%). 33 (37.9%) KPC-Kp strains were noticed to be in five transmission clusters (median number of isolates in each cluster: 5 [3-10]), four of them characterized by intra-hospital transmission. All 87 strains harbored Tn4401a transposon, carrying blaKPC-3 (48, 55.2%), blaKPC-2 (38, 43.7%), and in one case (1.2%) blaKPC-33, the latter gene conferred resistance to ceftazidime/avibactam (CZA). Thirty strains (34.5%) harbored porin mutations; of them, 7 (8.1%) carried multiple Tn4401a copies. These strains were characterized by significantly higher CZA minimum inhibitory concentration compared with strains with no porin mutations or single Tn4401a copy, respectively, even if they did not overcome the resistance breakpoint of 8 ug/mL. Median 2 (IQR:1-2) virulence factors per strain were detected. The lowest number was observed in ST20 compared to the other STs (p<0.001). While ST307 was associated with infection events, a trend associated with colonization events could be observed for ST20. CONCLUSIONS: Integration of genomic, resistance score, and clinical data allowed us to define a relative diversification of KPC-Kp in Northern Italy between 2019 and 2021, characterized by few large transmission chains and rare inter-hospital transmission. Our results also provided initial evidence of correlation between KPC-Kp genomic signatures and higher MIC levels to some antimicrobial agents or colonization/infection status, once again underlining WGS's importance in bacterial surveillance.


Asunto(s)
Antibacterianos , Proteínas Bacterianas , Infecciones por Klebsiella , Klebsiella pneumoniae , Humanos , Antibacterianos/farmacología , Proteínas Bacterianas/genética , beta-Lactamasas/genética , Infección Hospitalaria/microbiología , Infección Hospitalaria/epidemiología , Farmacorresistencia Bacteriana Múltiple/genética , Genoma Bacteriano , Genómica , Hospitales Universitarios , Italia/epidemiología , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/enzimología , Pruebas de Sensibilidad Microbiana , Secuenciación Completa del Genoma
15.
Cell Rep ; 43(8): 114520, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39024099

RESUMEN

We investigate JN.1-derived subvariants SLip, FLiRT, and KP.2 for neutralization by antibodies in vaccinated individuals, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients, or class III monoclonal antibody S309. Compared to JN.1, SLip, KP.2, and especially FLiRT exhibit increased resistance to bivalent-vaccinated and BA.2.86/JN.1-wave convalescent human sera. XBB.1.5 monovalent-vaccinated hamster sera robustly neutralize FLiRT and KP.2 but have reduced efficiency for SLip. All subvariants are resistant to S309 and show decreased infectivity, cell-cell fusion, and spike processing relative to JN.1. Modeling reveals that L455S and F456L in SLip reduce spike binding for ACE2, while R346T in FLiRT and KP.2 strengthens it. These three mutations, alongside D339H, alter key epitopes in spike, likely explaining the reduced sensitivity of these subvariants to neutralization. Our findings highlight the increased neutralization resistance of JN.1 subvariants and suggest that future vaccine formulations should consider the JN.1 spike as an immunogen, although the current XBB.1.5 monovalent vaccine could still offer adequate protection.


Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , SARS-CoV-2/inmunología , Animales , Humanos , Anticuerpos Neutralizantes/inmunología , COVID-19/inmunología , COVID-19/virología , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Cricetinae , Anticuerpos Antivirales/inmunología , Fusión de Membrana , Anticuerpos Monoclonales/inmunología , Mutación , Chlorocebus aethiops , Enzima Convertidora de Angiotensina 2/metabolismo , Epítopos/inmunología , Células Vero , Pruebas de Neutralización , Vacunas contra la COVID-19/inmunología
16.
Pharmaceutics ; 16(6)2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38931858

RESUMEN

Implementing the 3R initiative to reduce animal experiments in brain penetration prediction for CNS-targeting drugs requires more predictive in vitro and in silico models. However, animal studies are still indispensable to obtaining brain concentration and determining the prediction performance of in vitro models. To reveal species differences and provide reliable data for IVIVE, in vitro models are required. Systems overexpressing MDR1 and BCRP are widely used to predict BBB penetration, highlighting the impact of the in vitro system on predictive performance. In this study, endogenous Abcb1 knock-out MDCKII cells overexpressing MDR1 of human, mouse, rat or cynomolgus monkey origin were used. Good correlations between ERs of 83 drugs determined in each cell line suggest limited species specificities. All cell lines differentiated CNS-penetrating compounds based on ERs with high efficiency and sensitivity. The correlation between in vivo and predicted Kp,uu,brain was the highest using total ER of human MDR1 and BCRP and optimized scaling factors. MDR1 interactors were tested on all MDR1 orthologs using digoxin and quinidine as substrates. We found several examples of inhibition dependent on either substrate or transporter abundance. In summary, this assay system has the potential for early-stage brain penetration screening. IC50 comparison between orthologs is complex; correlation with transporter abundance data is not necessarily proportional and requires the understanding of modes of transporter inhibition.

17.
Mol Ther ; 32(7): 2064-2079, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38715361

RESUMEN

We investigated long-term human coagulation factor IX (huFIX) expression of a novel variant when delivered into mice and rhesus macaques and compared transduction efficiencies using two different adeno-associated virus (AAV) capsids. In hemophilic mice injected with KP1-packaged recombinant AAV (rAAV) expressing the hyperactive FIX variant specific activity plasma levels were 10-fold or 2-fold enhanced when compared with wild-type or Padua huFIX injected mice, respectively. In rhesus macaques AAV-LK03 capsid outperformed AAV-KP1 in terms of antigen expression and liver transduction. Two animals from each group showed sustained low-level huFIX expression at 3 months after administration, while one animal from each group lost huFIX mRNA and protein expression over time, despite comparable vector copies. We investigated whether epigenetic differences in the vector episomes could explain this loss of transcription. Cut&Tag analysis revealed lower levels of activating histone marks in the two animals that lost expression. When comparing rAAV genome associated histone modifications in rhesus macaques with those in mice injected with the same vector, the activating histone marks were starkly decreased in macaque-derived episomes. Differential epigenetic marking of AAV genomes may explain different expression profiles in mice and rhesus macaques, as well as the wide dose response variation observed in primates in both preclinical and human clinical trials.


Asunto(s)
Dependovirus , Epigénesis Genética , Factor IX , Vectores Genéticos , Macaca mulatta , Animales , Factor IX/genética , Factor IX/metabolismo , Dependovirus/genética , Ratones , Humanos , Vectores Genéticos/genética , Vectores Genéticos/administración & dosificación , Hemofilia B/genética , Hemofilia B/terapia , Transducción Genética , Terapia Genética/métodos
18.
Animals (Basel) ; 14(10)2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38791670

RESUMEN

The inevitable impacts of climate change have reverberated across ecosystems and caused substantial global biodiversity loss. Climate-induced habitat loss has contributed to range shifts at both species and community levels. Given the importance of identifying suitable habitats for at-risk species, it is imperative to assess potential current and future distributions, and to understand influential environmental factors. Like many species, the Demoiselle crane is not immune to climatic pressures. Khyber Pakhtunkhwa and Balochistan provinces in Pakistan are known wintering grounds for this species. Given that Pakistan is among the top five countries facing devastating effects of climate change, this study sought to conduct species distribution modeling under climate change using data collected during 4 years of field surveys. We developed a Maximum Entropy distribution model to predict the current and projected future distribution of the species across the study area. Future habitat projections for 2050 and 2070 were carried out using two representative concentration pathways (RCP 4.5 and RCP 8.5) under three global circulation models, including HADGEM2-AO, BCC-CSM1-1, and CCSM4. The most influential factors shaping Demoiselle Crane habitat suitability included the temperature seasonality, annual mean temperature, terrain ruggedness index, and human population density, all of which contributed significantly to the suitability (81.3%). The model identified 35% of the study area as moderately suitable (134,068 km2) and highly suitable (27,911 km2) habitat for the species under current climatic conditions. Under changing climate scenarios, our model predicted a major loss of the species' current suitable habitat, with shrinkage and shift towards western-central areas along the Pakistan-Afghanistan boarder. The RCP 8.5, which is the extreme climate change scenario, portrays particularly severe consequences, with habitat losses reaching 65% in 2050 and 85% in 2070. This comprehensive study provides useful insights into the Demoiselle Crane habitat's current and future dynamics in Pakistan.

19.
Cureus ; 16(4): e59094, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38800315

RESUMEN

Introduction Hypermucoviscous Klebsiella pneumoniae (hvKP) is related to invasive infections; however, there have been very few comprehensive reports on the clinical features and prognosis of critically ill patients with the infection. Methods We conducted a retrospective case series in a general intensive care unit in Japan. Patients with positive blood cultures for KP between January 1, 2020 and December 31, 2022 were included. hvKP was defined by the positivity in the string test. We analyzed the patient's characteristics at baseline, including comorbidities, abscess formation, Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score, septic shock, duration of hospitalization, 30-day mortality, and infection site. Results A total of 24 patients had a positive blood culture for KP; nine patients (37.5%) were positive for the string test (hvKP) while 15 (62.5%) were negative (non-hvKP). In both groups, the patients were old (mean age, hvKP 80.4 vs. non-hvKP 75.7 years) and more often male (five patients (55.6%) vs. 12 patients (80.0%)). No statistically significant difference was found between the two groups in terms of comorbidities, such as diabetes mellitus, chronic obstructive pulmonary disease, chronic kidney disease, and malignancy. No statistical difference was seen in abscess formation (two patients [22.2%] vs. one patient (6.7%)), SOFA score (5.2±4.8 vs. 4.7±3.4), APACHE II score (19.6 (15.0-20.0) vs. 17.0 (11.2-20.8)), septic shock (five patients (55.6%) vs. four patient (26.7%)), duration of hospitalization (37.2 (12.0-51.0) vs. 32.3 (9.5-21.0)), and 30-day mortality (two patients (22.2%) vs. two patients (13.3%)). Two cases with hvKP died within 24 h. No significant difference was seen in the infection sources; respiratory infection (2 (22.2%) vs. 1 (6.7%)), hepatobiliary infection (2 (22.2%) vs. 7 (46.7%)), and genitourinary infection (1 (11.1%) vs. 5 (33.3%)). Conclusions Critically ill patients with hvKP infection showed characteristics similar to those reported previously. However, the disease could rapidly become severe and have a poor prognostic outcome.

20.
Antibiotics (Basel) ; 13(5)2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38786129

RESUMEN

The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella Pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) is a group of bacteria very difficult to treat due to their high ability to acquire resistance to antibiotics and are the main cause of nosocomial infections worldwide, posing a threat to global public health. Nosocomial infections with MDR bacteria are found mainly in Intensive Care Units, due to the multitude of maneuvers and invasive medical devices used, the prolonged antibiotic treatments, the serious general condition of these critical patients, and the prolonged duration of hospitalization. MATERIALS AND METHODS: During a period of one year, from January 2023 to December 2023, this cross-sectional study was conducted on patients diagnosed with sepsis admitted to the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital. Samples taken were tracheal aspirate, catheter tip, pharyngeal exudate, wound secretion, urine culture, blood culture, and peritoneal fluid. RESULTS: The most common bacteria isolated from patients admitted to our Intensive Care Unit was Klebsiella pneumoniae, followed by Acinetobacter baumanii and Pseudomonas aeruginosa. Gram-positive cocci (Enterococcus faecium and Staphilococcus aureus) were rarely isolated. Most of the bacteria isolated were MDR bacteria. CONCLUSIONS: The rise of antibiotic and antimicrobial resistance among strains in the nosocomial environment and especially in Intensive Care Units raises serious concerns about limited treatment options.

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