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1.
Artigo em Inglês | MEDLINE | ID: mdl-39338144

RESUMO

The COVID-19 pandemic posed significant challenges to public health, exposing first responders to high biosafety risks during medical assistance and containment efforts. The PANDEM-2 study aimed to address these critical biosafety issues by emphasising the importance of frequently updated, harmonised guidelines. This study reviewed scientific publications, lessons learned, and real-world experiences from the COVID-19 pandemic to identify biorisk gaps in three critical areas: (i) patient transportation and management, (ii) sample handling and testing, and (iii) data management and communication by laboratory staff. At the onset of the pandemic, first responders faced several challenges, including the rapid expansion of emergency medical services, conversion of non-medical structures, increased internal and cross-border transport of infected patients, frequent changes in biosafety protocols, and a shortage of personal protective equipment. In response, this study developed a versatile and easily adaptable toolkit, including biosafety guidance and recommendations linked to updated national and international online repositories. It establishes the groundwork for a minimum standard that can be tailored to various pandemic response scenarios, using monkeypox as a fictive test case. The toolkit enables rapid access to updated information via QR codes and mobile devices, improving biorisk response by providing an adaptable and standardised approach for caregivers involved in national and cross-border responses.


Assuntos
COVID-19 , Pessoal de Saúde , COVID-19/prevenção & controle , Humanos , SARS-CoV-2 , Contenção de Riscos Biológicos/métodos , Pandemias , Equipamento de Proteção Individual , Transporte de Pacientes/métodos
2.
Emerg Microbes Infect ; 13(1): 2399950, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39259213

RESUMO

ABSTRACTBetween 2018 and 2024, we conducted systematic whole-genome sequencing and phylogenomic analysis on 263 V. cholerae O1 isolates from cholera patients across four provinces in the Democratic Republic of Congo (North-Kivu, South-Kivu, Tanganyika, and Kasai Oriental). These isolates were classified into the AFR10d and AFR10e sublineages of AFR10 lineage, originating from the third wave of the seventh El Tor cholera pandemic (7PET). Compared to the strains analysed between 2014 and 2017, both sublineages had few genetic changes in the core genome but recent isolates (2022-2024) had significant CTX prophage rearrangement. AFR10e spread across all four provinces, while AFR10d appeared to be extinct by the end of 2020. Since 2022, most V. cholerae O1 isolates exhibited significant CTX prophage rearrangements, including a tandem repeat of an environmental satellite phage RS1 downstream the ctxB toxin gene of the CTX-Φ-3 prophage on the large chromosome, as well as two or more arrayed copies of an environmental pre-CTX-Φ prophage precursor on the small chromosome. We used Illumina data for mapping and coverage estimation to identify isolates with unique CTX-Φ genomic features. Gene localization was then determined on MinION-derived assemblies, revealing an organization similar to that of non-O1 V. cholerae isolates found in Asia (O139 VC1374, and environmental O4 VCE232), but never described in V. cholerae O1 El Tor from the third wave. In conclusion, while the core genome of AFR10d and AFR10e showed minimal changes, significant alterations in the CTX-Φ and pre-CTX-Φ prophage content and organization were identified in AFR10e from 2022 onwards.


Assuntos
Cólera , Surtos de Doenças , Prófagos , Humanos , Cólera/microbiologia , Cólera/epidemiologia , Toxina da Cólera/genética , República Democrática do Congo/epidemiologia , Evolução Molecular , Genoma Bacteriano , Filogenia , Prófagos/genética , Vibrio cholerae/genética , Vibrio cholerae/virologia , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/classificação , Vibrio cholerae O1/genética , Vibrio cholerae O1/virologia , Vibrio cholerae O1/isolamento & purificação , Sequenciamento Completo do Genoma
3.
Artigo em Inglês | MEDLINE | ID: mdl-38248562

RESUMO

During the COVID-19 pandemic, first responders faced significant biosafety challenges, especially while handling patient transport, potentially exposing them to infection. The PANDEM-2 (European project on pandemic preparedness and response) project, funded by the Horizon 2020 program, sought to investigate the challenges confronting Emergency Medical Systems throughout the EU. First responders from Portugal's National Institute of Medical Emergency (INEM) were considered as a representative operational model of the national first responder agencies of European member states because they played a critical role during the COVID-19 pandemic. As a result, they were asked to complete an online survey about their COVID-19 pandemic-related professional activities. The survey focused on their perspectives on current biosafety guidelines and their operational practices. It covered opinions on existing protocols, technical concerns during patient transport, and issues after the patients arrived at the hospital. The key findings revealed concerns about risk assessment, the inadequacy of guidelines, and disparities in equipment access. This survey emphasizes the importance of developing streamlined, adaptable biosafety protocols, better coordination between prehospital and in-hospital services, and the development of scalable, cost-effective biosafety solutions. Based on our findings, we propose improvements to national and European biosafety directives and advocate for streamlined adaptation during pandemics.


Assuntos
COVID-19 , Serviços Médicos de Emergência , Humanos , Portugal/epidemiologia , Contenção de Riscos Biológicos , Pandemias , COVID-19/epidemiologia
4.
Epidemiol Infect ; 151: e167, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37724000

RESUMO

The Democratic Republic of the Congo (DRC) officially reports low coronavirus disease 19 (COVID-19) prevalence. This cross-sectional study, conducted between September and November 2021, assessed the COVID-19 seroprevalence in people attending Goma's two largest markets, Kituku and Virunga. A similar study in a slum of Bukavu overlapped for 1 month using identical methods. COVID-19-unvaccinated participants (n = 796 including 454 vendors and 342 customers, 60% of whom were women) were surveyed. The median age of vendors and customers was 34.2 and 30.1 years, respectively. The crude and adjusted anti-SARS-CoV-2 antibody seroprevalence rates were 70.2% (95% CI 66.9-73.4%) and 98.8% (95% CI 94.1-100%), respectively, with no difference between vendors and customers. COVID-19 symptoms reported by survey participants in the previous 6 months were mild or absent in 58.9% and 41.1% of participants with anti-SARS-CoV-2 antibodies, respectively. No COVID-19-seropositive participants reported hospitalisation in the last 6 months. These findings are consistent with those reported in Bukavu. They confirm that SARS-CoV-2 spread without causing severe symptoms in densely populated settlements and markets and suggest that many COVID-19 cases went unreported. Based on these results, the relevance of an untargeted hypothetical vaccination programme in these communities should be questioned.


Assuntos
COVID-19 , Humanos , Feminino , Masculino , Prevalência , República Democrática do Congo/epidemiologia , Estudos Transversais , Estudos Soroepidemiológicos , COVID-19/epidemiologia , SARS-CoV-2 , Anticorpos Antivirais
5.
Microbiol Resour Announc ; 12(6): e0007723, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37222607

RESUMO

Here, we present the complete coding sequences of two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains that were recovered from a nasopharyngeal swab from a female patient and the second viral passage in cell culture. After testing, both strains were identified as BA.5.2.20, a subvariant of Omicron.

6.
Microorganisms ; 11(2)2023 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-36838490

RESUMO

Multidrug-resistant (MDR) and extended spectrum ß-lactamase (ESBL)-producing extra-intestinal K. pneumoniae are associated with increased morbidity and mortality. This study aimed to characterize the resistance and virulence profiles of extra-intestinal MDR ESBL-producing K. pneumoniae associated with infections at a tertiary hospital in South-Kivu province, DRC. Whole-genome sequencing (WGS) was carried out on 37 K. pneumoniae isolates displaying MDR and ESBL-producing phenotype. The assembled genomes were analysed for phylogeny, virulence factors and antimicrobial resistance genes (ARG) determinants. These isolates were compared to sub-Saharan counterparts. K. pneumoniae isolates displayed a high genetic variability with up to 16 sequence types (ST). AMR was widespread against ß-lactamases (including third and fourth-generation cephalosporins, but not carbapenems), aminoglycosides, ciprofloxacin, tetracycline, erythromycin, nitrofurantoin, and cotrimoxazole. The blaCTX-M-15 gene was the most common ß-lactamase gene among K. pneumoniae isolates. No carbapenemase gene was found. ARG for aminoglycosides, quinolones, phenicols, tetracyclines, sulfonamides, nitrofurantoin were widely distributed among the isolates. Nine isolates had the colistin-resistant R256G substitution in the pmrB efflux pump gene without displaying reduced susceptibility to colistin. Despite carrying virulence genes, none had hypervirulence genes. Our results highlight the genetic diversity of MDR ESBL-producing K. pneumoniae isolates and underscore the importance of monitoring simultaneously the evolution of phenotypic and genotypic AMR in Bukavu and DRC, while calling for caution in administering colistin and carbapenem to patients.

7.
Epidemiol Infect ; 151: e24, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36775822

RESUMO

Data on coronavirus disease 2019 (COVID-19) prevalence in the Democratic Republic of Congo are scarce. We conducted a cross-sectional study to determine the seroprevalence of antibodies against anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the slum of Kadutu, city of Bukavu, between June and September 2021. The survey participants were all unvaccinated against SARS-CoV-2. The crude seroprevalence rate was adjusted to the known characteristics of the assay. Participants aged 15-49 years old made up 80% of the population enrolled in the study (n = 507; 319 women and 188 men). The overall crude and adjusted seroprevalence rates of antibodies for COVID-19 were 59.7% (95% CI 55.4-63.9%) and 84.0% (95% CI 76.2-92.4%), respectively. This seroprevalence rate indicates widespread dissemination of SARS-CoV-2 in these communities. COVID-19 symptoms were either absent or mild in more than half of the participants with antibodies for COVID-19 and none of the participants with antibodies for COVID-19 required hospitalisation. These results suggest that SARS-CoV-2 spread did not appear to be associated with severe symptoms in the population of these settlements and that many cases went unreported in these densely populated locations. The relevance of vaccination in these communities should be thoroughly investigated.


Assuntos
COVID-19 , Masculino , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , COVID-19/epidemiologia , SARS-CoV-2 , Estudos Transversais , República Democrática do Congo/epidemiologia , Estudos Soroepidemiológicos , Anticorpos , Anticorpos Antivirais
8.
Microb Drug Resist ; 29(5): 165-174, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35852864

RESUMO

In this study, we assessed the potential of bacteriocins and their in vitro synergistic effects in combination with anti-tuberculosis drugs against Mycobacterium tuberculosis. We evaluated the in vitro activity of chemically synthesized bacteriocins in combination with rifampicin (RIF), ofloxacin, and moxifloxacin against the reference M. tuberculosis H37Rv and a clinical-resistant strain. We first screened the bacteriocin PARAGEN collection and found active bacteriocins. We then determined their minimal inhibitory concentration (MIC), minimal bactericidal concentration, and their fractional inhibitory index by the checkerboard microdilution assay. Remarkably, we identified four bacteriocins with interesting antimycobacterial activity alone and in combinations with RIF, ofloxacin, and moxifloxacin, with significant reduction of the MIC that showed impressive synergistic effects against the susceptible and resistant clinical strains. In conclusion, our preliminary results show promising bacteriocins candidate used in a synergistic combination with anti-tuberculosis drugs and emphasize the need for combined therapy as a new strategy to enhance the activity of existing drugs, which may confer very promising therapeutic benefits against M. tuberculosis.


Assuntos
Bacteriocinas , Mycobacterium tuberculosis , Moxifloxacina/farmacologia , Bacteriocinas/farmacologia , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Rifampina/farmacologia , Ofloxacino/farmacologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-36141839

RESUMO

The Biological Light Fieldable Laboratory for Emergencies (B-LiFE) is a box-based modular laboratory with the capacity to quickly deploy on-site in cases of uncontrolled spread of infectious disease. During the 2014-2015 West Africa Ebola outbreak, this tent laboratory provided diagnostic support to the N'Zerekore Ebola Treatment Center (ETC), Guinea, for three months. One of the objectives of B-LiFE deployment was to contribute, as much as possible, to national capacity building by training local scientists. Two Guinean biologists were selected according to their basic biological knowledge and laboratory skills among 50 candidate trainees, and were integrated into the team through "just-in-time training" (JiTT), which helped the biologists acquire knowledge and laboratory skills beyond their expertise. The JiTT program was conducted according to standard laboratory procedures, in line with international biosafety guidelines adapted to field conditions. Supervised acquisition of field-laboratory practices mainly focused on biochemical testing and Ebola viral load quantification using routine PCR-based detection, including the Biofire FilmArray® system (BFA), a novel, as yet non-validated, automated assay for diagnostic testing of Ebola virus disease at the time of B-LiFE deployment. During the JiTT, the two biologists were closely involved in all laboratory activities, including BFA validation and biosafety procedures. Meanwhile, this successful JiTT enhanced the B-LiFE in-field operational capacity and contributed to national capacity building. A post-training evaluation and contacts were organised to assess the evolution and technical skills gained by the two researchers during the B-LiFE mission. At the end of the B-LiFE mission, both biologists were enrolled in follow-on programmes to curb the epidemic spreading in Africa. These results demonstrate that during infectious disease outbreaks or major crises, the JiTT approach can rapidly expand access to critical diagnostic testing and train local staff to do so.


Assuntos
Doença pelo Vírus Ebola , África Ocidental/epidemiologia , Contenção de Riscos Biológicos , Surtos de Doenças/prevenção & controle , Emergências , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos
10.
Microorganisms ; 10(7)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35889078

RESUMO

Dependence on multiple nutritional bacterial symbionts forming a metabolic unit has repeatedly evolved in many insect species that feed on nutritionally unbalanced diets such as plant sap. This is the case for aphids of the subfamilies Lachninae and Chaitophorinae, which have evolved di-symbiotic systems in which the ancient obligate nutritional symbiont Buchnera aphidicola is metabolically complemented by an additional nutritional symbiont acquired more recently. Deciphering how different symbionts integrate both metabolically and anatomically in such systems is crucial to understanding how complex nutritional symbiotic systems function and evolve. In this study, we sequenced and analyzed the genomes of the symbionts B. aphidicola and Serratia symbiotica associated with the Chaitophorinae aphids Sipha maydis and Periphyllus lyropictus. Our results show that, in these two species, B. aphidicola and S. symbiotica complement each other metabolically (and their hosts) for the biosynthesis of essential amino acids and vitamins, but with distinct metabolic reactions supported by each symbiont depending on the host species. Furthermore, the S. symbiotica symbiont associated with S. maydis appears to be strictly compartmentalized into the specialized host cells housing symbionts in aphids, the bacteriocytes, whereas the S. symbiotica symbiont associated with P. lyropictus exhibits a highly invasive phenotype, presumably because it is capable of expressing a larger set of virulence factors, including a complete flagellum for bacterial motility. Such contrasting levels of metabolic and anatomical integration for two S. symbiotica symbionts that were recently acquired as nutritional co-obligate partners reflect distinct coevolutionary processes specific to each association.

11.
Parasit Vectors ; 14(1): 578, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789326

RESUMO

BACKGROUND: Pulsed ultraviolet (UV)-C light sources, such as excimer lasers, are used in emerging non-thermal food-decontamination methods and also have high potential for use in a wide range of microbial decontamination applications. The acaricidal effect of an experimental UV-C irradiation device was assessed using female adults and eggs of a model organism, the two-spotted spider mite Tetranychus urticae. METHODS: UV-C light was generated by a pulsed krypton fluoride excimer laser operating at 248-nm emission wavelength. The pulse energy and pulse repetition rate were 5 mJ and up to 100 Hz, respectively. The distance from the light source to the target was 150 mm; the target surface area was 2.16 cm2. The exposure time for the mites and fresh eggs varied from 1 to 4 min at 5-300 mW, which corresponded to UV doses of 5-80 kJ/m2. Post-irradiation acaricidal effects (mite mortality) were assessed immediately and also measured at 24 h. The effects of UV-C irradiation on the hatchability of eggs were observed daily for up to 12 days post-irradiation. RESULTS: The mortality of mites at 5 and 40 kJ/m2 was 26% and 92%, respectively. Mite mortality reached 98% at 80 kJ/m2. The effect of exposure duration on mortality was minimal. The effect of irradiation on egg hatchability was even more significant than that on adult mite mortality, i.e. about 100% egg mortality at an accumulated dose of as little as 5 kJ/m2 for each exposure time. CONCLUSIONS: A high rate of mite mortality and lethal egg damage were observed after less than 1 min of exposure to 5 mJ UV-C pulsed irradiation at 60 Hz. Pending further developments (such as beam steering, beam shaping and miniaturisation) and feasibility studies (such as testing with mites in real-life situations), the reported results and characteristics of the UV-C generator (modulation of energy output and adaptability to varying spot sizes) open up the use of this technology for a vast field of acaricidal applications that require long-range radiation.


Assuntos
Controle de Pragas/métodos , Tetranychidae , Raios Ultravioleta , Acaricidas , Animais , Feminino , Lasers de Excimer , Ácaros , Mortalidade
12.
Artigo em Inglês | MEDLINE | ID: mdl-34501606

RESUMO

In the case of rapid outbreaks of infectious diseases in remote locations, the lack of real-time information from the field and rapid spread of misinformation can be a major issue. To improve situational awareness and decision-making at all levels of operational deployment, there is an urgent need for accurate, reliable, and timely results from patients from the affected area. This requires a robust and fast channel of communication connecting first responders on-site, crisis managers, decision-makers, and the institutions involved in the survey of the crisis at national, regional, and international levels. This has been the rationale sustaining the development of advanced communication tools in the Biological Light Fieldable Laboratory for Emergencies (B-LiFE). The benefit of terrestrial (TETRA, LTE, 5G, and Wi-Fi-Fi) and SatCom communications is illustrated through a series of missions and exercises conducted in the previous five years. These tools were used by B-LiFE operators to provide accurate, comprehensive, timely, and relevant information and services in real time. The focus of this article is to discuss the development and benefits of the integration of multi-mission, multi-user nomadic, rapidly deployable telecommunication nodes for emergency uses (TEN) in the capacity of B-LiFE. Providing reliable communication channels through TEN enables the development and use of an ICT toolbox called MIML_LIMS (multi-institution, multi-mission, multi-laboratory LIMS), a tool which is mandatory for efficient and secure data management and data sharing by a mobile laboratory.


Assuntos
Gerenciamento de Dados , Telecomunicações , Humanos , Disseminação de Informação , Laboratórios , Saúde Pública
13.
PLoS One ; 16(8): e0256019, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34379678

RESUMO

Many insect species are associated with bacterial partners that can significantly influence their evolutionary ecology. Compared to other insect groups, aphids harbor a bacterial microbiota that has the reputation of being poorly diversified, generally limited to the presence of the obligate nutritional symbiont Buchnera aphidicola and some facultative symbionts. In this study, we analyzed the bacterial diversity associated with the dogwood-grass aphid Anoecia corni, an aphid species that spends much of its life cycle in a subterranean environment. Little is known about the bacterial diversity associated with aphids displaying such a lifestyle, and one hypothesis is that close contact with the vast microbial community of the rhizosphere could promote the acquisition of a richer bacterial diversity compared to other aphid species. Using 16S rRNA amplicon Illumina sequencing on specimens collected on wheat roots in Morocco, we identified 10 bacterial operational taxonomic units (OTUs) corresponding to five bacterial genera. In addition to the obligate symbiont Buchnera, we identified the facultative symbionts Serratia symbiotica and Wolbachia in certain aphid colonies. The detection of Wolbachia is unexpected as it is considered rare in aphids. Moreover, its biological significance remains unknown in these insects. Besides, we also detected Arsenophonus and Dactylopiibacterium carminicum. These results suggest that, despite its subterranean lifestyle, A. corni shelter a bacterial diversity mainly limited to bacterial endosymbionts.


Assuntos
Afídeos/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Biodiversidade , Evolução Biológica , Variação Genética , Simbiose , Animais , Bactérias/genética , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota , Marrocos , Filogenia , Análise de Sequência de DNA
14.
Sci Rep ; 11(1): 16740, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408169

RESUMO

The coronavirus pandemic, which appeared in Wuhan, China, in December 2019, rapidly spread all over the world in only a few weeks. Faster testing techniques requiring less resources are key in managing the pandemic, either to enable larger scale testing or even just provide developing countries with limited resources, particularly in Africa, means to perform tests to manage the crisis. Here, we report an unprecedented, rapid, reagent-free and easy-to-use screening spectroscopic method for the detection of SARS-CoV-2 on RNA extracts. This method, validated on clinical samples collected from 280 patients with quantitative predictive scores on both positive and negative samples, is based on a multivariate analysis of FTIR spectra of RNA extracts. This technique, in agreement with RT-PCR, achieves 97.8% accuracy, 97% sensitivity and 98.3% specificity while reducing the testing time post RNA extraction from hours to minutes. Furthermore, this technique can be used in several laboratories with limited resources.


Assuntos
Teste para COVID-19/métodos , RNA Viral/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , RNA Viral/química , RNA Viral/isolamento & purificação , Fatores de Tempo
15.
Parasit Vectors ; 14(1): 426, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34446077

RESUMO

BACKGROUND: Toxocara canis and Toxocara cati are globally distributed roundworms and causative agents of human toxocariasis, via ingestion of Toxocara eggs. Control of Toxocara infections is constrained by a lack of sensitive methods for screening of animal faeces and environmental samples potentially contaminated by Toxocara eggs. In this work, a pre-analytical method for efficient extraction of DNA from Toxocara eggs in environmental samples was set up using our previously validated T. canis- and T. cati-specific quantitative real-time polymerase chain reaction (qPCR). For this purpose, the influence of different methods for egg lysis, DNA extraction and purification for removal of PCR inhibitors were assessed on environmental samples. METHODS: To select the best egg disruption method, six protocols were compared on pure T. canis egg suspensions, including enzymatic lysis and thermal or mechanical disruption. Based on the selected best method, an analytical workflow was set up to compare two DNA extraction methods (FastDNA™ SPIN Kit for Soil versus DNeasy® PowerMax® Soil Kit) with an optional dilution and/or clean-up (Agencourt® AMPure®) step. This workflow was evaluated on 10-g soil and 10-g sand samples spiked with egg suspensions of T. canis (tenfold dilutions of 104 eggs in triplicate). The capacity of the different methods, used alone or in combination, to increase the ratio of positive tests was assessed. The resulting optimal workflow for processing spiked soil samples was then tested on environmental soil samples and compared with the conventional flotation-centrifugation and microscopic examination of Toxocara eggs. RESULTS: The most effective DNA extraction method for Toxocara eggs in soil samples consisted in the combination of mechanical lysis of eggs using beads, followed by DNA extraction with the DNeasy® PowerMax® Soil Kit, and completed with an additional DNA clean-up step with AMPure® beads and a sample DNA dilution (1:10). This workflow exhibited a limit of detection of 4 and 46 T. canis eggs in 10-g sand and 10-g soil samples, respectively. CONCLUSIONS: The pre-analytical flow process developed here combined with qPCR represents an improved, potentially automatable, and cost-effective method for the surveillance of Toxocara contamination in the environment.


Assuntos
DNA de Helmintos/genética , Óvulo , Contagem de Ovos de Parasitas/métodos , Areia/parasitologia , Solo/parasitologia , Toxocara canis/genética , Animais , Reação em Cadeia da Polimerase em Tempo Real , Especificidade da Espécie
16.
Front Immunol ; 12: 666107, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34194430

RESUMO

Macrophages are not only derived from circulating blood monocytes or embryonic precursors but also expand by proliferation. The origin determines macrophage fate and functions in steady state and pathological conditions. Macrophages predominantly infiltrate fibre-induced mesothelioma tumors and contribute to cancer development. Here, we revealed their ontogeny by comparing the response to needle-like mesotheliomagenic carbon nanotubes (CNT-7) with tangled-like non-mesotheliomagenic CNT-T. In a rat peritoneal cavity model of mesothelioma, both CNT induced a rapid macrophage disappearance reaction (MDR) of MHCIIlow resident macrophages generating an empty niche available for macrophage repopulation. Macrophage depletion after mesotheliomagenic CNT-7 was followed by a substantial inflammatory reaction, and macrophage replenishment completed after 7 days. Thirty days after non-mesotheliomagenic CNT-T, macrophage repopulation was still incomplete and accompanied by a limited inflammatory reaction. Cell depletion experiments, flow cytometry and RNA-seq analysis demonstrated that, after mesotheliomagenic CNT-7 exposure, resident macrophages were mainly replaced by an influx of monocytes, which differentiated locally into MHCIIhigh inflammatory macrophages. In contrast, the low inflammatory response induced by CNT-T was associated by the accumulation of self-renewing MHCIIlow macrophages that initially derive from monocytes. In conclusion, the mesotheliomagenic response to CNT specifically relies on macrophage niche recolonization by monocyte-derived inflammatory macrophages. In contrast, the apparent homeostasis after non-mesotheliomagenic CNT treatment involves a macrophage regeneration by proliferation. Macrophage depletion and repopulation are thus decisive events characterizing the carcinogenic activity of particles and fibres.


Assuntos
Macrófagos/imunologia , Mesotelioma/imunologia , Monócitos/imunologia , Nanotubos de Carbono/efeitos adversos , Animais , Diferenciação Celular , Proliferação de Células , Antígenos de Histocompatibilidade Classe II/metabolismo , Inflamação , Macrófagos/citologia , Macrófagos/metabolismo , Mesotelioma/induzido quimicamente , Monócitos/citologia , Monócitos/metabolismo , Neutrófilos/citologia , Neutrófilos/imunologia , Cavidade Peritoneal/citologia , Ratos
17.
J Glob Antimicrob Resist ; 26: 335-341, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34303856

RESUMO

OBJECTIVES: Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli are an increasingly significant cause of hospital- and community-acquired infections worldwide. Whereas several reports have highlighted their increased prevalence also in North African countries, genomic data on isolates associated with these infections are still scarce. This study aimed to provide data on ESBL-producing E. coli isolates from patients with extraintestinal infections at the Military Teaching Hospital Mohamed V of Rabat, Morocco. METHODS: Whole-genome sequencing was carried out on 18 ESBL-producing extraintestinal pathogenic E. coli (ExPEC) isolates for analysis of phylogenomic evolution, virulence factors and antimicrobial resistance genes. Data were compared with ExPEC lineages from several surrounding countries using multilocus sequence typing (MLST) and single nucleotide polymorphism-based phylogenetic approaches. RESULTS: The majority of E. coli isolates were ST131 (n = 15), followed by ST617 (n = 2) and a novel sequence type (ST10703) that is closely related to the pandemic ST405 clone. All ST131 isolates belonged to the O25b-ST131 pandemic clone. They harboured more virulence genes than their non-ST131 counterparts. IncF plasmid replicons and the blaCTX-M-15 ß-lactamase gene were identified in all isolates. No ESBL-producing E. coli isolates carried any known carbapenemase gene. CONCLUSION: Our findings underscore the pre-eminence of ST131 as the major factor driving the expansion of ExPEC in the Rabat region while highlighting the potential links with isolates circulating in other neighbouring countries.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Genômica , Humanos , Marrocos/epidemiologia , Tipagem de Sequências Multilocus , Filogenia , beta-Lactamases/genética
18.
Front Cell Infect Microbiol ; 11: 660007, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34268133

RESUMO

Mutualistic associations between insects and heritable bacterial symbionts are ubiquitous in nature. The aphid symbiont Serratia symbiotica is a valuable candidate for studying the evolution of bacterial symbiosis in insects because it includes a wide diversity of strains that reflect the diverse relationships in which bacteria can be engaged with insects, from pathogenic interactions to obligate intracellular mutualism. The recent discovery of culturable strains, which are hypothesized to resemble the ancestors of intracellular strains, provide an opportunity to study the mechanisms underlying bacterial symbiosis in its early stages. In this study, we analyzed the genomes of three of these culturable strains that are pathogenic to aphid hosts, and performed comparative genomic analyses including mutualistic host-dependent strains. All three genomes are larger than those of the host-restricted S. symbiotica strains described so far, and show significant enrichment in pseudogenes and mobile elements, suggesting that these three pathogenic strains are in the early stages of the adaptation to their host. Compared to their intracellular mutualistic relatives, the three strains harbor a greater diversity of genes coding for virulence factors and metabolic pathways, suggesting that they are likely adapted to infect new hosts and are a potential source of metabolic innovation for insects. The presence in their genomes of secondary metabolism gene clusters associated with the production of antimicrobial compounds and phytotoxins supports the hypothesis that S. symbiotia symbionts evolved from plant-associated strains and that plants may serve as intermediate hosts. Mutualistic associations between insects and bacteria are the result of independent transitions to endosymbiosis initiated by the acquisition of environmental progenitors. In this context, the genomes of free-living S. symbiotica strains provide a rare opportunity to study the inventory of genes held by bacterial associates of insects that are at the gateway to a host-dependent lifestyle.


Assuntos
Afídeos , Simbiose , Animais , Afídeos/genética , Genoma Bacteriano , Genômica , Filogenia , Serratia
19.
Food Chem Toxicol ; 154: 112352, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34153347

RESUMO

BACKGROUND: Nanotechnologies provide new opportunities for improving the safety, quality, shelf life, flavor and appearance of foods. The most common nanoparticles (NPs) in human diet are silver metal, mainly present in food packaging and appliances, and silicon and titanium dioxides used as additives. The rapid development and commercialization of consumer products containing these engineered NPs is, however, not well supported by appropriate toxicological studies and risk assessment. Local and systemic toxicity and/or disruption of the gut microbiota (GM) have already been observed after oral administration of NPs in experimental animals, but results are not consistent and doses used were often much higher than the estimated human intakes. In view of the strong evidence linking alterations of the GM to cardiometabolic (CM) diseases, we hypothesized that dietary NPs might disturb this GM-CM axis. MATERIALS AND METHODS: We exposed male C57BL/6JRj mice (n = 13 per dose group) to dietary NPs mixed in food pellets at doses relevant for human exposure: Ag (0, 4, 40 or 400 µg/kg pellet), SiO2 (0, 0.8, 8 and 80 mg/kg pellet) or TiO2 (0, 0.4, 4 or 40 mg/kg pellet). After 24 weeks of exposure, we assessed effects on the GM and CM health (n = 8 per dose group). The reversibility of the effects was examined after 8 additional weeks without NPs exposure (recovery period, n ≤ 5 per dose group). RESULTS: No overt toxicity was recorded. The GM ß-diversity was dose-dependently disrupted by the three NPs, and the bacterial short chain fatty acids (SCFAs) were dose-dependently reduced after the administration of SiO2 and TiO2 NPs. These effects disappeared completely or partly after the recovery period, strengthening the association with dietary NPs. We did not observe atheromatous disease or glucose intolerance after NP exposure. Instead, dose-dependent decreases in the expression of IL-6 in the liver, circulating triglycerides (TG) and urea nitrogen (BUN) were recorded after administration of the NPs. CONCLUSION: We found that long-term oral exposure to dietary NPs at doses relevant for estimated human intakes disrupts the GM composition and function. These modifications did not appear associated with atheromatous or deleterious metabolic outcomes.


Assuntos
Exposição Dietética/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Nanopartículas Metálicas/química , Administração Oral , Animais , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Ácidos Graxos Voláteis/metabolismo , Interleucina-6/metabolismo , Masculino , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/toxicidade , Camundongos Endogâmicos C57BL , Dióxido de Silício/administração & dosagem , Dióxido de Silício/farmacologia , Dióxido de Silício/toxicidade , Prata/administração & dosagem , Prata/farmacologia , Prata/toxicidade , Titânio/administração & dosagem , Titânio/farmacologia , Titânio/toxicidade , Triglicerídeos/metabolismo
20.
Artigo em Inglês | MEDLINE | ID: mdl-33805139

RESUMO

Coronavirus disease 2019 (COVID-19) is an acute infectious disease caused by the novel coronavirus (SARS-CoV-2) identified in 2019. The COVID-19 outbreak continues to have devastating consequences for human lives and the global economy. The B-LiFe mobile laboratory in Piedmont, Italy, was deployed for the surveillance of COVID-19 cases by large-scale testing of first responders. The objective was to assess the seroconversion among the regional civil protection (CP), police, health care professionals, and volunteers. The secondary objective was to detect asymptomatic individuals within this cohort in the light of age, sex, and residence. In this paper, we report the results of serological testing performed by the B-LiFe mobile laboratory deployed from 10 June to 23 July 2020. The tests included whole blood finger-prick and serum sampling for detection of SARS-CoV-2 spike receptor-binding domain (S-RBD) antibodies. The prevalence of SARS-CoV-2 antibodies was approximately 5% (294/6013). The results of the finger-prick tests and serum sample analyses showed moderate agreement (kappa = 0.77). Furthermore, the detection rates of serum antibodies to the SARS-CoV-2 nucleocapsid protein (NP) and S-RBD among the seroconverted individuals were positively correlated (kappa = 0.60), at least at the IgG level. Seroprevalence studies based on serological testing for the S-RBD protein or SARS-CoV-2 NP antibodies are not sufficient for diagnosis but might help in screening the population to be vaccinated and in determining the duration of seroconversion.


Assuntos
COVID-19 , Laboratórios , Anticorpos Antivirais , Teste para COVID-19 , Humanos , Imunoglobulina G , Imunoglobulina M , Itália/epidemiologia , SARS-CoV-2 , Estudos Soroepidemiológicos
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