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1.
Cell ; 174(1): 102-116.e14, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29804837

RESUMEN

RAG endonuclease initiates antibody heavy chain variable region exon assembly from V, D, and J segments within a chromosomal V(D)J recombination center (RC) by cleaving between paired gene segments and flanking recombination signal sequences (RSSs). The IGCR1 control region promotes DJH intermediate formation by isolating Ds, JHs, and RCs from upstream VHs in a chromatin loop anchored by CTCF-binding elements (CBEs). How VHs access the DJHRC for VH to DJH rearrangement was unknown. We report that CBEs immediately downstream of frequently rearranged VH-RSSs increase recombination potential of their associated VH far beyond that provided by RSSs alone. This CBE activity becomes particularly striking upon IGCR1 inactivation, which allows RAG, likely via loop extrusion, to linearly scan chromatin far upstream. VH-associated CBEs stabilize interactions of D-proximal VHs first encountered by the DJHRC during linear RAG scanning and thereby promote dominant rearrangement of these VHs by an unanticipated chromatin accessibility-enhancing CBE function.


Asunto(s)
Factor de Unión a CCCTC/metabolismo , Cromatina/metabolismo , Proteínas de Homeodominio/metabolismo , Recombinación V(D)J , Animales , Línea Celular , ADN Intergénico/genética , ADN Intergénico/metabolismo , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/metabolismo , Región Variable de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/metabolismo , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Mutagénesis , Señales de Clasificación de Proteína , ARN Guía de Kinetoplastida/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo
2.
J Gen Virol ; 105(3)2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38506716

RESUMEN

PCV2 belongs to the genus Circovirus in the family Circoviridae, whose genome is replicated by rolling circle replication (RCR). PCV2 Rep is a multifunctional enzyme that performs essential functions at multiple stages of viral replication. Rep is responsible for nicking and ligating single-stranded DNA and unwinding double-stranded DNA (dsDNA). However, the structure and function of the Rep are still poorly understood, which significantly impedes viral replication research. This study successfully resolved the structure of the PCV2 Rep ATPase domain (PRAD) using X-ray crystallography. Homologous structure search revealed that Rep belonged to the superfamily 3 (SF3) helicase, and multiple conserved residues were identified during sequence alignment with SF3 family members. Simultaneously, a hexameric PRAD model was generated for analysing characteristic structures and sites. Mutation of the conserved site and measurement of its activity showed that the hallmark motifs of the SF3 family influenced helicase activity by affecting ATPase activity and ß-hairpin just caused the loss of helicase activity. The structural and functional analyses of the PRAD provide valuable insights for future research on PCV2 replication and antiviral strategies.


Asunto(s)
Circovirus , Porcinos , Animales , Circovirus/genética , Adenosina Trifosfatasas/genética , Cristalografía por Rayos X , ADN Helicasas/genética , Replicación del ADN
3.
Chembiochem ; : e202400287, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39045641

RESUMEN

Yellow fluorescent proteins (YFPs) are commonly used in biology to track cellular processes, particularly as acceptors in experiments using the Förster Resonant Energy Transfer (FRET) phenomenon. However, their fluorescence intensity is strongly pH-dependent, limiting their utility in acidic environments. Here, we explore the pH sensitivity of YFPs upon binding with an artificial repeat protein (αRep) both in vitro and in living cells. We show that αRep binds to Citrine, with high affinity in the nanomolar range at physiological and acidic pHs, leading to increased thermal stability of the complex. Moreover, αRep binding reduces Citrine's pKa by 0.75 pH units, leading to a decreased sensitivity to pH fluctuations. This effect can be generalized to other YFPs as Venus and EYFP in vitro. An efficient binding of αRep to Citrine has also been observed in living cells both at pH 7.4 and pH 6. This interaction leads to reduced variations of Citrine fluorescence intensity in response to pH variations in cells. Overall, the study highlights the potential of αReps as a tool to modulate the pH sensitivity of YFPs, paving the way for future exploration of biological events in acidic environments by FRET in combination with a pH-insensitive cyan donor.

4.
Microb Pathog ; 195: 106916, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39236969

RESUMEN

In this work, the antibiotic resistance, biofilm formation capability, and clonal relatedness of 50 A. baumannii isolates collected from three hospitals in Ardabil city, Iran, were evaluated. Antibiotic sensitivity and biofilm formation of isolates were determined by disk diffusion and microtiter-plate methods, respectively. Molecular typing of isolates was also performed using repetitive sequence-based PCR (REP-PCR). The majority of isolates were resistant to cephems, aminoglycosides, and carbapenems, with 80 % classified as multi-drug resistant (MDR). While, only isolates collected from blood and tracheal were resistant to colistin. Additionally, 42 isolates (84 %) had biofilm formation capability. According to rep-PCR results, 34 isolates showed similar banding patterns, while 16 isolates had unique banding patterns. Finally, based on the molecular analysis, there was a direct relationship between biofilm formation and the antibiotic resistance of isolates. In other words, MDR isolates had a higher ability to form biofilm.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Biopelículas , Farmacorresistencia Bacteriana Múltiple , Pruebas de Sensibilidad Microbiana , Biopelículas/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Humanos , Antibacterianos/farmacología , Infecciones por Acinetobacter/microbiología , Irán , Farmacorresistencia Bacteriana Múltiple/genética , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Acinetobacter baumannii/aislamiento & purificación , Acinetobacter baumannii/fisiología , Tipificación Molecular , Reacción en Cadena de la Polimerasa , Colistina/farmacología , Adulto , Hospitales , Masculino , Femenino , Genotipo , Persona de Mediana Edad
5.
Plasmid ; 129-130: 102722, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38631562

RESUMEN

The predominant type of plasmids found in Acinetobacter species encode a Rep_3 initiation protein and many of these carry their accessory genes in dif modules. Here, available sequences of the 14 members of the group of Rep_3 plasmids typed as R3-T33, using a threshold of 95% identity in the repA gene, were compiled and compared. These plasmids were from various Acinetobacter species. The pdif sites were identified allowing the backbone and dif modules to be defined. As for other Rep_3 plasmids carrying dif modules, orfX encoding a protein of unknown function was found downstream of repA followed by a pdif site in the orientation XerC binding site-spacer-XerD binding site. Most backbones (n = 12) also included mobA and mobC genes but the two plasmids with the most diverged repA and orfX genes had different backbone contents. Although the gene content of the plasmid backbone was largely conserved, extensive recombinational exchange was detected and only two small groups carried identical or nearly identical backbones. Individual plasmids were associated with 1 to 13 dif modules. Many different dif modules were identified, including ones containing antibiotic or chromate resistance genes and several toxin/antitoxin gene pairs. In some cases, modules carrying the same genes were significantly diverged. Generally, the orientation of the pdif sites alternated such that C modules (XerC binding sites internal) alternated with D modules (XerD binding sites internal). However, fusions of two dif modules via mutational inactivation or loss of a pdif site were also detected.


Asunto(s)
Acinetobacter , Plásmidos , Acinetobacter/genética , Plásmidos/genética , Plásmidos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sitios de Unión , ADN Bacteriano/genética , Secuencia de Bases , Filogenia , Transactivadores/genética , Transactivadores/metabolismo , ADN Helicasas
6.
Mol Biol Rep ; 51(1): 566, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38656625

RESUMEN

BACKGROUND: Escherichia coli is the most common etiological agent of urinary tract infections (UTIs). Meanwhile, plasmid-mediated quinolone resistance (PMQR) is reported in E. coli isolates producing extended-spectrum ß-lactamases (ESBLs). Furthermore, the reservoirs and mechanisms of acquisition of uropathogenic Escherichia coli (UPEC) strains are poorly understood. On the other hand, UTIs are common in pregnant women and the treatment challenge is alarming. METHODS AND RESULTS: In the present study, 54 pregnant women with acute cystitis were included. A total of 108 E. coli isolates, 54 isolates from UTI and 54 isolates from faeces of pregnant women (same host) were collected. In the antimicrobial susceptibility test, the highest rate of antibiotic resistance was to nalidixic acid (77%, 83/108) and the lowest rate was to imipenem (9%, 10/108). Among the isolates, 44% (48/108) were ESBLs producers. A high frequency of PMQR genes was observed in the isolates. The frequency of PMQR genes qnrS, qnrB, aac(6')-Ib-cr, and qnrA was 58% (63/108), 21% (23/108), 9% (10/108), and 4% (4/108), respectively. Meanwhile, PMQR genes were not detected in 24% (20/85) of isolates resistant to nalidixic acid and/or fluoroquinolone, indicating that other mechanisms, i.e. chromosomal mutations, are involved in resistance to quinolones, which were not detected in the present study. In ESBL-producing isolates, the frequency of PMQR genes was higher than that of non-ESBL-producing isolates (81% vs. 53%). Meanwhile, UTI and faeces isolates mainly belonged to phylogenetic group B2 (36/54, 67% and 25/54, 46%, respectively) compared to other phylogenetic groups. In addition, virulence factors and multidrug-resistant (MDR) were mainly associated with phylogenetic group B2. However, predominant clones in faeces were not found in UTIs. Rep-PCR revealed the presence of 85 clones in patients. Among the clones, 40 clones were detected only in faeces (faeces-only), 35 clones only in UTI (UTI-only) and 10 clones in both faeces and UTI (faeces-UTI). We found that out of 10 faeces-UTI clones, 5 clones were present in the host's faeces flora. CONCLUSION: This study revealed a high rate of resistance to the quinolone nalidixic acid and a widespread distribution of PMQR genes in MDR E. coli strains producing ESBLs. The strains represented virulence factors and phylogenetic group B2 are closely associated with abundance in UTI and faeces. However, the predominant clones in faeces were not found in UTIs and it is possible that rep-PCR is not sufficiently discriminating clones.


Asunto(s)
Antibacterianos , Cistitis , Infecciones por Escherichia coli , Escherichia coli , Heces , Pruebas de Sensibilidad Microbiana , Plásmidos , Quinolonas , beta-Lactamasas , Humanos , Femenino , beta-Lactamasas/genética , Plásmidos/genética , Heces/microbiología , Quinolonas/farmacología , Embarazo , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/tratamiento farmacológico , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Adulto , Antibacterianos/farmacología , Cistitis/microbiología , Farmacorresistencia Bacteriana/genética , Prevalencia , Infecciones Urinarias/microbiología , Ácido Nalidíxico/farmacología
7.
J Appl Microbiol ; 135(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38419289

RESUMEN

AIMS: The work presented here was conducted to characterize the biodiversity of a collection of bacterial isolates, mainly wood endophytes, as part of a research project focused on exploring their bioprotective potential for postharvest biological control of fruits. METHODS AND RESULTS: This work was the basis for the development of a tailored method combining 16S rDNA sequencing and Rep-PCR to differentiate the isolates and identify them to genus level or below. More than one hundred isolates obtained from wood and roots of different grapevine genotypes were cultured on appropriate growth media and then subjected to the specified multistep molecular identification. CONCLUSIONS: We have obtained good dereplication for grapevine-endophytic bacteria, together with reliable genetic identification. Both are essential prerequisites to properly characterize a biome bank and, at the same time, beneficial prerequisites to subsequently perform a correct bioprotection assessment.


Asunto(s)
Bacterias , Endófitos , ARN Ribosómico 16S/genética , Biodiversidad , Análisis de Secuencia de ADN , Raíces de Plantas/microbiología , Filogenia
8.
Soc Psychiatry Psychiatr Epidemiol ; 59(10): 1671-1684, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38329495

RESUMEN

PURPOSE: This report provides the results of a task-shared approach for integrating care for perinatal depression (PND) within primary maternal and child healthcare (PMCH), including the factors that may facilitate or impede the process. METHODS: This hybrid implementation-effectiveness study guided by the Replicating Effective Programmes framework was conducted in 27 PMCH clinics in Ibadan, Nigeria. The primary implementation outcome was change in the identification rates of PND by primary health care workers (PHCW) while the primary effectiveness outcome was the difference in symptom remission (EPDS score ≤ 5) 6 months postpartum. Outcome measures were compared between two cohorts of pregnant women, one recruited before and the other after training PHCW to identify and treat PND. Barriers and facilitators were explored in qualitative interviews. RESULTS: Identification of PND improved from 1.4% before to 17.4% after training; post-training rate was significantly higher in clinics where PHCW routinely screened using the 2-item patient health questionnaire (24.8%) compared to non-screening clinics (5.6%). At 6-months postpartum, 60% of cohort one experienced remission from depression, compared to 56.5% cohort two [OR-0.9 (95%CI-0.6, 1.3) p = 0.58]. Identified facilitators for successful integration included existence of policy specifying mental health as a component of PHC, use of screening to aid identification and supportive supervision, while barriers included language and cultural attitudes towards mental health and human resource constraints. PHCW were able to make adaptations to address these barriers. CONCLUSIONS: Successful implementation of task-shared care for perinatal depression requires addressing staff shortages and adopting strategies that can improve identification by non-specialist providers. TRIAL REGISTRATION: This study was retrospectively registered 03 Dec 2019. https://doi.org/10.1186/ISRCTN94230307 .


Asunto(s)
Prestación Integrada de Atención de Salud , Atención Primaria de Salud , Humanos , Femenino , Nigeria , Atención Primaria de Salud/organización & administración , Embarazo , Adulto , Prestación Integrada de Atención de Salud/organización & administración , Depresión Posparto/terapia , Depresión/terapia , Atención Perinatal/organización & administración , Complicaciones del Embarazo/terapia , Personal de Salud/psicología
9.
World J Microbiol Biotechnol ; 40(4): 122, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38441818

RESUMEN

This study was conducted for identifying phylogenetic relationships between 15 scab-causing Streptomyces species including S. bottropensis, S. europaeiscabiei, S. scabiei, S. stelliscabiei and, other 11 Streptomyces sp. All of the strains were originally isolated from symptomatic potatoes in Erzurum Province, The Eastern Anatolia Region of Turkey. Some morphological and biochemical properties of the strains were defined in our former research. Then, 16 s rRNA regions of them were sequenced. After the sequence data assembly, phylogenetic analyzes were performed. The phylogenetic analyses revealed that the strains are involved in the same major group and, substantially similar to reference strains. Additionally, some subgroup formations were also recorded. Moreover, Repetitive element-based PCR (Rep-PCR), Enterobacterial repetitive intergenic consensus (ERIC-PCR), and BOX-PCR fingerprinting molecular typing methods were used for as molecular typing methods. According to our knowledge, this is the first report on phylogenetic relationships of scab-causing Streptomyces species from Turkey. However, the identification of most pathogenic strains remained at the species level.


Asunto(s)
Enterobacteriaceae , Streptomyces , Turquía , Filogenia , Tipificación Molecular , Streptomyces/genética
10.
Proteins ; 91(8): 1130-1139, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37171131

RESUMEN

Porcine circovirus type 2 (PCV2) can cause porcine circovirus-associated disease (PCVAD), which causes significant economic losses to the global pig industry annually. There are no effective antiviral drugs used to control and treat PCV2, and prevention is mainly obtained through vaccination. PCV2 genome replicates through the rolling circle replication (RCR) mechanism involving Rep and Rep', so analyzing the holistic structure of Rep and Rep' will help us better understand the replication process of PCV2. However, there are no reports on the integral structure of Rep' and Rep, which seriously hinders the research of the viral replication. By using the x-ray diffraction method, the structure of the Rep' dimer was resolved by us in this study. Structural analysis revealed that Rep' is a dimer formed by the interaction of the C-terminal domain. The two Rep' form a positively charged groove, which may play an essential role in the viral binding of dsDNA. Together, this study help to understand the replication process of the virus and may also provide new insights into the development of antiviral drugs.


Asunto(s)
Circovirus , Proteínas Virales , Animales , Porcinos , Proteínas Virales/química , Circovirus/genética , Circovirus/metabolismo , Replicación Viral/genética
11.
J Gen Virol ; 104(6)2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37326617

RESUMEN

Geminivirus-betasatellite disease complexes are an epidemic threat to the majority of economically important crops across the world. Plant virus satellites including betasatellites are maintained by their associated helper virus. Geminivirus-betasatellites influence viral pathogenesis by substantially increasing or decreasing their helper virus accumulation. In the present study, we attempted to understand the mechanistic details of the geminivirus-betasatellite interaction. Here, we used tomato leaf curl Gujarat virus (ToLCGV) and tomato leaf curl Patna betasatellite (ToLCPaB) as a model system. This study reveals that ToLCGV can efficiently trans-replicate ToLCPaB in Nicotiana benthamiana plants, but ToLCPaB greatly reduced the accumulation of its helper virus DNA. For the first time, we have identified that the ToLCPaB-encoded ßC1 protein is able to interact with ToLCGV-encoded replication initiator protein (Rep). In addition, we demonstrate that the C-terminal region of ßC1 interacts with the C-terminus of Rep (RepC) protein. Our previous study had established that ßC1 proteins encoded by diverse betasatellites possess a novel ATP hydrolysis activity and the conserved lysine/arginine residues at positions 49 and 91 are necessary for this function. Here, we show that mutating lysine at positions 49 to alanine of ßC1 (ßC1K49A) protein did not affect its ability to interact with RepC protein. Biochemical studies performed with ATP hydrolysis activity-deficient K49A mutated ßC1 (ßC1K49A) and RepC proteins revealed that Rep-ßC1 interaction interferes with the ATP hydrolysis activity of Rep protein. Further, we demonstrate that ßC1 protein is able to interact with D227A and D289A mutated RepC proteins but not with D262A, K272A or D286A mutated RepC proteins, suggesting that the ßC1-interacting region of Rep protein encompasses its Walker-B and B' motifs. The results of docking studies supported that the ßC1-interacting region of Rep protein encompasses its motifs associated with ATP binding and ATP hydrolysis activities. Docking studies also provided evidence that the Rep-ßC1 interaction interferes with the ATP binding activity of Rep protein. Together, our findings suggest that ßC1 protein regulates helper virus accumulation by interfering with the ATP hydrolysis activity of helper virus Rep protein.


Asunto(s)
Begomovirus , Geminiviridae , Geminiviridae/genética , Virus Helper , Lisina/metabolismo , Hidrólisis , Proteínas Virales/genética , Proteínas Virales/metabolismo , Begomovirus/genética , Adenosina Trifosfato/metabolismo , Enfermedades de las Plantas , Nicotiana
12.
J Viral Hepat ; 30 Suppl 1: 33-38, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36529713

RESUMEN

Hepatitis delta virus (HDV) is a small RNA virus which needs Hepatitis B Surface Antigen for its envelope, for entry into hepatocytes and secretion. HDV chronic infection affects around 12 million people worldwide. HDV infection is believed to be the most severe form of viral hepatitis, with a high risk of developing cirrhosis and hepatocellular carcinoma. Pegylated interferons has been used and recommended by guidelines, although not approved, with low efficacy and poor tolerability. Bulevirtide (entry inhibitor) has been recently conditionally approved by the European Medicines Agency. These treatments have many advantages, but they have also limitations since there are non-responders to these previous therapies. There is an urgent need to develop new drugs. In this article, we review antiviral treatments under development for HDV chronic infection (except bulevirtide reviewed in a specific article), including those in the HBV cure programme, outlining their respective mechanisms-of-action.


Asunto(s)
Virus de la Hepatitis Delta , Neoplasias Hepáticas , Humanos , Virus de la Hepatitis Delta/genética , Infección Persistente , Antivirales/efectos adversos , Neoplasias Hepáticas/tratamiento farmacológico , Virus de la Hepatitis B
13.
Arch Microbiol ; 205(4): 114, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36907935

RESUMEN

Bacillus species are among the most researched and frequently applied biocontrol agents. To estimate their potential as environmentally friendly microbial-based products, reliable and rapid plant colonization monitoring methods are essential. We evaluated repetitive element-based (rep) and Random Amplified Polymorphic DNA (RAPD) PCR (Polymerase Chain Reaction) genotyping in a diversity assessment of 251 strains from bulk soil, straw, and manure samples across Serbia, highlighting their discriminative force and the presence of unique bands. RAPD 272, OPG 5, and (GTG)5 primers were most potent in revealing the high diversity of a sizable environmental Bacillus spp. collection. RAPD 272 also amplified a unique band for a proven biocontrol strain, opening the possibility of Sequence Characterized Amplified Region (SCAR) marker design. That will enable colonization studies using the SCAR marker for its specific detection. This study provides a guide for primer selection for diversity and monitoring studies of environmental Bacillus spp. isolates.


Asunto(s)
Bacillus , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Bacillus/genética , Genotipo , Reacción en Cadena de la Polimerasa/métodos , ADN/genética , Biomarcadores
14.
Plant Cell Rep ; 42(7): 1125-1132, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37127835

RESUMEN

KEY MESSAGE: Novel episomal systems have the potential to accelerate plastid genetic engineering for application in plant synthetic biology. Plastids represent valuable subcellular compartments for genetic engineering of plants with intrinsic advantages to engineering the nucleus. The ability to perform site-specific transgene integration by homologous recombination (HR), coordination of transgene expression in operons, and high production of heterologous proteins, all make plastids an attractive target for synthetic biology. Typically, plastid engineering is performed by homologous recombination; however, episomal-replicating vectors have the potential to accelerate the design/build/test cycles for plastid engineering. By accelerating the timeline from design to validation, it will be possible to generate translational breakthroughs in fields ranging from agriculture to biopharmaceuticals. Episomal-based plastid engineering will allow precise single step metabolic engineering in plants enabling the installation of complex synthetic circuits with the ambitious goal of reaching similar efficiency and flexibility of to the state-of-the-art genetic engineering of prokaryotic systems. The prospect to design novel episomal systems for production of transplastomic marker-free plants will also improve biosafety for eventual release in agriculture.


Asunto(s)
Ingeniería Genética , Plastidios , Ingeniería Genética/métodos , Plastidios/genética , Plastidios/metabolismo , Plantas/genética , Transgenes/genética , Ingeniería Metabólica , ADN/metabolismo , Plantas Modificadas Genéticamente/genética , Transformación Genética
15.
BMC Pediatr ; 23(1): 59, 2023 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-36737722

RESUMEN

BACKGROUND: Escherichia coli serogroup O25b-sequence type 131 (E. coli O25-B2-ST131) is considered as multidrug-resistant and hypervirulent organism. There is lack of data about involvement of this pathogen in the children's infection. In this study, the prevalence, and clonality, virulence capacity, and antibiotic resistance phenotype and genotype of E. coli O25-B2-ST131 compared with non-O25-B2-ST131 isolates were investigated in children with urinary tract infection in Tehran, Iran. METHODS: The E. coli isolates from urine samples were identified using conventional microbiological methods. Characterization of E. coli O25-B2-ST131 clone, antibiotic susceptibility, biofilm formation, ESBLs phenotype and genotype, serum resistance, hemolysis, hydrophobicity, and formation of curli fimbriae were done using conventional microbiological and molecular methods. Clonality of the isolates was done by rep-PCR typing. RESULTS: Among 120 E. coli isolates, the highest and lowest antibiotic resistance was detected against ampicillin (92, 76.6%) and imipenem 5, (4.1%), respectively. Sixty-eight (56.6%) isolates were ESBL-producing and 58 (48.3%) isolates were considered as multi-drug resistance (MDR). The prevalence of ESBL-producing and MDR isolates in O25-B2-ST131 strains was higher compared with the non-O25-B2-ST131 strains (p value < 0.05). O25-B2-ST131 strains showed significant correlation with serum resistance and biofilm formation. Amongst the resistance and virulence genes, the prevalence of iucD, kpsMTII, cnf1, vat, blaCTX-M-15, and blaSHV were significantly higher among O25-B2-ST131 isolates in comparison with non-O25-B2-ST131 isolates (p value < 0.05). Considering a ≥ 80% homology cut-off, fifteen different clusters of the isolates were shown with the same rep-PCR pattern. CONCLUSIONS: Our results confirmed the involvement of MDR-ESBLs producing E. coli strain O25-B2-ST131 in the occurrence of UTIs among children. Source tracking and control measures seem to be necessary for containment of the spread of hypervirulent and resistance variants in children.


Asunto(s)
Infecciones por Escherichia coli , Infecciones Urinarias , Humanos , Escherichia coli/genética , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Virulencia/genética , Pruebas de Sensibilidad Microbiana , Irán/epidemiología , Genotipo , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/microbiología , Farmacorresistencia Microbiana , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Fenotipo , beta-Lactamasas/genética
16.
Food Microbiol ; 109: 104138, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36309440

RESUMEN

The bacterial diversity and load on equipment in food processing facilities is constantly influenced by raw material, water, air, and staff. Despite regular cleaning and disinfection, some bacteria may persist and thereby potentially compromise food quality and safety. Little is known about how bacterial communities in a new food processing facility gradually establish themselves. Here, the development of bacterial communities in a newly opened salmon processing plant was studied from the first day and during the first year of operation. To focus on the persisting bacterial communities, surface sampling was done on strategical sampling points after cleaning and disinfection. To study the diversity dynamics, isolates from selected sampling and time points were classified by Oxford Nanopore Technology-based rep-PCR amplicon sequencing (ON-rep-seq) supplemented by 16S rRNA gene or rpoD gene sequencing (for Pseudomonas). An overall increase in bacterial numbers was only observed for food-contact surfaces in the slaughter department, but not in filleting department, on non-food contact surfaces or on the fish. Changes in temporal and spatial diversity and community composition were observed and our approach revealed highly point-specific bacterial communities.


Asunto(s)
Microbiología de Alimentos , Salmón , Animales , Bacterias , Manipulación de Alimentos , ARN Ribosómico 16S/genética , Microbiota
17.
J Dairy Res ; 90(2): 146-151, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37326242

RESUMEN

We compared the virulence profile and REP-PCR genotypes of Escherichia coli strains isolated from subclinical and clinical mastitis cases and dairy farm environments in Minas Gerais State, Brazil, to determine virulence factors and genotypes potentially associated with subclinical persistence in the udder. The virulence profile was obtained by the search for three virulence genes: lpfA (long polar fimbriae), fliC (flagella), and escN (type III secretion system). Subclinical isolates exhibited mainly the fliC gene (33.33%) and fliC + escN genes (30.30%). Clinical isolates exhibited mainly fliC + escN genes (50%) and environmental isolates the lpfA + escN genes (58.04%). Strains isolated from subclinical mastitis showed 6.75 times more positivity to fliC than environmental isolates. Thirty-four genotypes were observed in the REP-PCR analysis, and clinical mastitis isolates indicated more genetic proximity to dairy farm environment isolates than subclinical mastitis isolates. In conclusion, the results suggested that flagella may be an important virulence factor for mammary persistent E. coli infection in cattle, however, none of the E. coli REP-PCR genotypes were associated with subclinical infection.


Asunto(s)
Enfermedades de los Bovinos , Infecciones por Escherichia coli , Mastitis Bovina , Animales , Bovinos , Femenino , Escherichia coli , Factores de Virulencia/genética , Infecciones por Escherichia coli/veterinaria , Flagelos
18.
New Microbiol ; 46(3): 278-284, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37747473

RESUMEN

In this study the antibiotic susceptibility pattern and bla genes were characterized in Klebsiella pneumoniae clinical isolates that fingerprinted by rep-PCR and PFGE methods at Kurdistan Province, Iran. A total of 70 K. pneumoniae were isolated from clinical samples to detect the antimicrobial susceptibility, carbapenemase and MBL-producing isolates. The PCR assay was used to identify the bla genes. Isolates were typed by PFGE and Rep-PCR methods. The highest and lowest rates of resistance were observed in cefotaxime (67.1%) and imipenem (8.6%), respectively. The rate of blaNDM-1 and blaOXA-48 genes were 1 (1.4%) and 14 (20%) isolates, respectively. All were classified in 27 clusters by rep-PCR and 39 PFGE types. The low frequency of carbapenemase and MBL genes in this study are epidemiologically important.


Asunto(s)
Infección Hospitalaria , Klebsiella pneumoniae , Humanos , Epidemiología Molecular , Klebsiella pneumoniae/genética , Infección Hospitalaria/epidemiología , Tipificación Molecular , Reacción en Cadena de la Polimerasa
19.
Int J Mol Sci ; 24(18)2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37762657

RESUMEN

Choroideremia is an X-linked retinal degeneration resulting from the progressive, centripetal loss of photoreceptors and choriocapillaris, secondary to the degeneration of the retinal pigment epithelium. Affected individuals present in late childhood or early teenage years with nyctalopia and progressive peripheral visual loss. Typically, by the fourth decade, the macula and fovea also degenerate, resulting in advanced sight loss. Currently, there are no approved treatments for this condition. Gene therapy offers the most promising therapeutic modality for halting or regressing functional loss. The aims of the current review are to highlight the lessons learnt from clinical trials in choroideremia, review endpoints, and propose a future strategy for clinical trials.


Asunto(s)
Coroideremia , Ceguera Nocturna , Niño , Adolescente , Humanos , Coroideremia/genética , Coroideremia/terapia , Coroides , Fóvea Central , Terapia Genética
20.
Environ Monit Assess ; 195(4): 496, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36947259

RESUMEN

Understanding the actual distribution of different Legionella species in water networks would help prevent outbreaks. Culture investigations followed by serological agglutination tests, with poly/monovalent antisera, still represent the gold standard for isolation and identification of Legionella strains. However, also MALDI-TOF and mip-gene sequencing are currently used. This study was conducted to genetically correlate strains of Legionella non pneumophila (L-np) isolated during environmental surveillance comparing different molecular techniques. Overall, 346 water samples were collected from the water system of four pavilions located in a hospital of the Apulia Region of Italy. Strains isolated from the samples were then identified by serological tests, MALDI-TOF, and mip-gene sequencing. Overall, 24.9% of water samples were positive for Legionella, among which the majority were Legionella pneumophila (Lpn) 1 (52.3%), followed by Lpn2-15 (20.9%), L-np (17.4%), Lpn1 + Lpn2-15 (7.1%), and L-np + Lpn1 (2.3%). Initially, L-np strains were identified as L. bozemanii by monovalent antiserum, while MALDI-TOF and mip-gene sequencing assigned them to L. anisa. More cold water than hot water samples were contaminated by L. anisa (p < 0.001). PFGE, RAPD, Rep-PCR, and SAU-PCR were performed to correlate L. anisa strains. Eleven out of 14 strains identified in all four pavilions showed 100% of similarity upon PFGE analysis. RAPD, Rep-PCR, and SAU-PCR showed greater discriminative power than PFGE.


Asunto(s)
Monitoreo del Ambiente , Hospitales , Microbiología del Agua , Abastecimiento de Agua , Monitoreo del Ambiente/métodos , Italia , Técnicas Microbiológicas/normas , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Legionella/genética , Legionella/aislamiento & purificación , Análisis de Secuencia de ADN
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