- Volume 72, Issue 10, 2023
Volume 72, Issue 10, 2023
- Editorials
- JMM Profiles
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Avian reovirus: a furious and fast evolving pathogen
More LessAvian reoviruses (ARVs) have a significant economic impact on the poultry industry, affecting commercial and backyard flocks. Spread feco-orally, or vertically, many do not cause morbidity, but pathogenic strains can contribute to several diseases, including tenosynovitis/arthritis, which is clinically the most significant. The last decade has seen a surge in cases in the US, and due to ongoing evolution, seven genotypic clusters have now been identified. Control efforts include strict biosecurity and vaccination with commercial and autogenous vaccines. Research priorities include improving understanding of pathogenesis and developing new vaccines guided by ongoing molecular and serologic surveillance.
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- Antimicrobial Resistance
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Efficacy of ceftobiprole in a murine model of bacteremia and disseminated infection
More LessIntroduction. Ceftobiprole is an advanced-generation broad-spectrum parenteral cephalosporin with activity against MSSA and MRSA.
Gap Statement. Ceftobiprole is not currently approved for use to treat S. aureus bacteremia and phase three clinical trials are taking place. Drug approval requires further pre-clinical evidence to support this new indication.
Aim. The aim of this study was to evaluate the efficacy of ceftobiprole at the human equivalent efficacious exposure (considering a 500 mg q8h dosing regimen infused over 2 h) against MSSA and MRSA strains in a neutropenic murine model of bacteremia and disseminated infection.
Methodology. Two bioluminescent-tagged strains (one MSSA and one MRSA strain) were selected based on their in vitro susceptibility and in vivo growth profiles. Bacterial c.f.u. counts in the blood, lung, kidney, and liver were determined 48 h post-infection or after death. The bioluminescent-tag allowed the visualization of the real-time effects of ceftobiprole therapy compared to the natural progression of the infection in untreated controls.
Results. Treatment with ceftobiprole resulted in a significant reduction of the bacterial load with the bioluminescence reduced by 2-log units and bacterial c.f.u. counts reduced by 3- to 6-log units, depending on the organ and bacterial strain. Survival was 100 % in the ceftobiprole-treated group compared to only 0–20 % survival in the untreated control animals for both strains tested.
Conclusion. These results suggest that treatment with ceftobiprole using a 500 mg q8h dosing regimen studied in several successful phase three trials, has potential as an antibiotic therapy to treat bacteremia and associated disseminated infections caused by either methicillin-susceptible or methicillin-resistant strains of S. aureus .
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Analysis of possible pathways on the mechanism of action of minocycline and doxycycline against strains of Candida spp. resistant to fluconazole
Cecília Rocha da Silva, Maria Janielly Castelo Branco Silveira, Giulia Caetano Soares, Claudia Roberta de Andrade, Vitória Pessoa de Farias Cabral, Lívia Gurgel do Amaral Valente Sá, Daniel Sampaio Rodrigues, Lara Elloyse Almeida Moreira, Amanda Dias Barbosa, Lisandra Juvêncio da Silva, Anderson Ramos da Silva, Akenaton Onassis Cardoso Viana Gomes, Bruno Coêlho Cavalcanti, Manoel Odorico de Moraes, Hélio Vitoriano Nobre Júnior and João Batista de Andrade NetoSpecies of the genus Candida, characterized as commensals of the human microbiota, are opportunistic pathogens capable of generating various types of infections with high associated costs. Considering the limited pharmacological arsenal and the emergence of antifungal-resistant strains, the repositioning of drugs is a strategy used to search for new therapeutic alternatives, in which minocycline and doxycycline have been evaluated as potential candidates. Thus, the objective was to evaluate the in vitro antifungal activity of two tetracyclines, minocycline and doxycycline, and their possible mechanism of action against fluconazole-resistant strains of Candida spp. The sensitivity test for antimicrobials was performed using the broth microdilution technique, and the pharmacological interaction with fluconazole was also analysed using the checkerboard method. To analyse the possible mechanisms of action, flow cytometry assays were performed. The minimum inhibitory concentration obtained was 4–427 µg ml−1 for minocycline and 128–512 µg ml−1 for doxycycline, and mostly indifferent and additive interactions with fluconazole were observed. These tetracyclines were found to promote cellular alterations that generated death by apoptosis, with concentration-dependent reactive oxygen species production and reduced cell viability. Therefore, minocycline and doxycycline present themselves as promising study molecules against Candida spp.
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- Disease, Diagnosis and Diagnostics
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Rapid response of a public health reference laboratory to the COVID-19 pandemic
Juliana Maira Watanabe Pinhata, Angela Pires Brandao, Daniela Leite, Rosangela Siqueira de Oliveira, Lucila Okuyama Fukasawa, Maria Gisele Gonçalves, Juliana Mariotti Guerra, Leonardo José Tadeu de Araujo, Gina Ploeger Mansueli, Lilian Beserra Santos, Tarcilla Corrente Borghesan, Lidia Midori Kimura, Juliana Possatto Fernandes Takahashi, Juliana Alves Garcia, Ana Rita de Toledo Piza, Camila Santos da Silva Ferreira, Ricardo Polatto, Maria Luiza Leopoldo e Silva Guerra, Raquel dos Anjos Fazioli, Rosemeire Cobo Zanella, Roberta Morozetti Blanco and IAL-2 Working Group†Introduction. Brazil was one of the most affected countries by the COVID-19 pandemic. Instituto Adolfo Lutz (IAL) is the reference laboratory for COVID-19 in São Paulo, the most populous state in Brazil. In April 2020, a secondary diagnostic pole named IAL-2 was created to enhance IAL’s capacity for COVID-19 diagnosis.
Hypothesis/Gap Statement. Public health laboratories must be prepared to rapidly respond to emerging epidemics or pandemics.
Aim. To describe the design of IAL-2 and correlate the results of RT-qPCR tests for COVID-19 with secondary data on suspected cases of SARS-CoV-2 infection in the São Paulo state.
Methodology. This is a retrospective study based on the analysis of secondary data from patients suspected of infection by SARS-CoV-2 whose clinical samples were submitted to real-time PCR after reverse transcription (RT-qPCR) at IAL-2, between 1 April 2020 and 8 March 2022. RT-qPCR Ct results of the different kits used were also analysed.
Results. IAL-2 was implemented in April 2020, just over a month after the detection of the first COVID-19 case in Brazil. The laboratory performed 304,250 RT-qPCR tests during the study period, of which 98 319 (32.3 %) were positive, 205827 (67.7 %) negative, and 104 (0.03 %) inconclusive for SARS-CoV-2. RT-qPCR Ct values≤30 for E/N genes of SARS-CoV-2 were presented by 79.7 % of all the samples included in the study.
Conclusion. IAL was able to rapidly implement a new laboratory structure to support the processing of an enormous number of samples for diagnosis of COVID-19, outlining strategies to carry out work with quality, using different RT-qPCR protocols.
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- Microbiome and Microbial Ecology in Health
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Microbiome depiction through user-adapted bioinformatic pipelines and parameters
Introduction. The role of the microbiome in health and disease continues to be increasingly recognized. However, there is significant variability in the bioinformatic protocols for analysing genomic data. This, in part, has impeded the potential incorporation of microbiomics into the clinical setting and has challenged interstudy reproducibility. In microbial compositional analysis, there is a growing recognition for the need to move away from a one-size-fits-all approach to data processing.
Gap Statement. Few evidence-based recommendations exist for setting parameters of programs that infer microbiota community profiles despite these parameters significantly impacting the accuracy of taxonomic inference.
Aim. To compare three commonly used programs (DADA2, QIIME2, and mothur) and optimize them into four user-adapted pipelines for processing paired-end amplicon reads. We aim to increase the accuracy of compositional inference and help standardize microbiomic protocol.
Methods. Two key parameters were isolated across four pipelines: filtering sequence reads based on a whole-number error threshold (maxEE) and truncating read ends based on a quality score threshold (QTrim). Closeness of sample inference was then evaluated using a mock community of known composition.
Results. We observed that raw genomic data lost were proportionate to how stringently parameters were set. Exactly how much data were lost varied by pipeline. Accuracy of sample inference correlated with increased sequence read retention. Falsely detected taxa and unaccounted for microbial constituents were unique to pipeline and parameter. Implementation of optimized parameter values led to better approximation of the known mock community.
Conclusions. Microbial compositions generated based on the 16S rRNA marker gene should be interpreted with caution. To improve microbial community profiling, bioinformatic protocols must be user-adapted. Analysis should be performed with consideration for the select target amplicon, pipelines and parameters used, and taxa of interest.
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- Pathogenesis, Virulence and Host Response
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Molecular mechanism of Enteroaggregative Escherichia coli induced apoptosis in cultured human intestinal epithelial cells
More LessBackground. Enteroaggregative Escherichia coli (EAEC) is an evolving etiological agent of acute and persistent diarrhoea worldwide. The previous study from our laboratory has reported the apoptosis-inducing activity of EAEC in human small intestinal and colonic epithelial cell lines. In the present investigation, we have explored the underlying mechanism of EAEC-induced apoptosis in human intestinal epithelial cell lines.
Methods. INT-407 and HCT-15 cells were infected with EAEC-T8 and EAEC-pT8 (plasmid cured strain of EAEC-T8) separately. Cells cultured in the absence of bacteria served as a negative control in all the experiments. For the subsequent experiments, the molecular mechanism(s) of epithelial cell aposptosis was measured in EAEC infecting both the cell lines by flow cytometry, real-time PCR and Western blotting.
Results and conclusions. EAEC was found to activate the intrinsic/mitochondrial apoptotic pathway in both the cell lines through upregulation of pro-apoptotic Bax and Bak, un-alteration/reduction in the level of anti-apoptotic Bcl-2 and Bcl-XL, decrease in mitochondrial transmembrane potential, accumulation of cytosolic cytochrome c leading to activation of procaspase-9 and procaspase-3, which ultimately resulted in DNA fragmentation and apoptosis. Further, an increased expression of Fas, activation of procaspase-8 and upregulation of pro-apoptotic Bid in the EAEC-infected cells indicated the involvement of extrinsic apoptotic pathway too in this process. Our finding has undoubtedly led to an increased understanding of EAEC pathogenesis, which may be helpful to develop an improved strategy to combat the infection.
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- Prevention, Therapy and Therapeutics
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Explore intersection genes of oxymatrine and COVID-19 with lung cancer as potential therapeutic targets based on network pharmacology
Wei Wu, Chuan Cheng, Dongdong Yuan, Li Peng and Le LiIntroduction. Oxymatrine is a natural quinazine alkaloid extracted from Sophora flavescens and has many medicinal values. Oxymatrine showed protective effects, viral inhibition and effects against lung cancer.
Hypothesis/Gap Statement. Individuals with lung cancer exhibit heightened vulnerability to COVID-19 infection due to compromised immune function. In conjunction with COVID-19, it is hypothesized that oxymatrine may exert potent pharmacological effects on lung cancer patients.
Aim. The objective of this study was to assess the pharmacological mechanisms and targets of oxymatrine in relation to COVID-19 lung cancer.
Methodology. Utilizing network pharmacology analysis, a selection of 2628 genes were identified as co-targets for both COVID-19 and lung cancer. Subsequently, a clinicopathological analysis was conducted by integrating RNA-Seq and clinical data obtained from the TCGA-LUAD lung cancer dataset, which was acquired from the official TCGA website. The identification of pharmacological targets for oxymatrine was accomplished through the utilization of various databases including Pharm mapper, SWISS Target prediction, and STITCH. These identified targets were further investigated for protein-protein interaction (PPI) using STRING, as well as for gene ontology (GO) and KEGG pathways.
Results. The effects of oxymatrine on COVID-19-induced lung cancer were mediated by immune regulation, cytoprotection, antiviral, and anti-inflammatory activities, immune regulation, and control of related signalling pathways, including the formation of the neutrophil extracellular trap, phagosome, Toll-like receptor signalling pathway, apoptosis, proteoglycans in cancer, extracellular matrix disassembly, and proteolysis involved in cellular protein catabolism. Furthermore, important substances and genes like ALB, MMP3, MMP1, and TLR4 may affect how oxymatrine suppresses lung cancer/COVID-19 development.
Conclusion. To treat COVID-19 or lung cancer paired with COVID-19, oxymatrine may improve the therapeutic efficacy of current clinical antiviral medicines and immunotherapy.
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- Corrigenda
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Volumes and issues
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Volume 73 (2024)
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Volume 72 (2023 - 2024)
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Volume 71 (2022)
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Volume 70 (2021)
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Volume 69 (2020)
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Volume 68 (2019)
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Volume 67 (2018)
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Volume 66 (2017)
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Volume 65 (2016)
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Volume 64 (2015)
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Volume 63 (2014)
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Volume 62 (2013)
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Volume 61 (2012)
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Volume 60 (2011)
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Volume 59 (2010)
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Volume 58 (2009)
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Volume 57 (2008)
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Volume 56 (2007)
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Volume 55 (2006)
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Volume 54 (2005)
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Volume 53 (2004)
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Volume 52 (2003)
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Volume 51 (2002)
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Volume 50 (2001)
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Volume 49 (2000)
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Volume 48 (1999)
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Volume 47 (1998)
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Volume 46 (1997)
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Volume 45 (1996)
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Volume 44 (1996)
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Volume 43 (1995)
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Volume 42 (1995)
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Volume 41 (1994)
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Volume 40 (1994)
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Volume 39 (1993)
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Volume 38 (1993)
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Volume 37 (1992)
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Volume 36 (1992)
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Volume 35 (1991)
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Volume 34 (1991)
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Volume 33 (1990)
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Volume 32 (1990)
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Volume 31 (1990)
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Volume 30 (1989)
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Volume 29 (1989)
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Volume 28 (1989)
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Volume 27 (1988)
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Volume 26 (1988)
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Volume 25 (1988)
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Volume 24 (1987)
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Volume 23 (1987)
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Volume 22 (1986)
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Volume 21 (1986)
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Volume 20 (1985)
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Volume 19 (1985)
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Volume 18 (1984)
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Volume 17 (1984)
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Volume 16 (1983)
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Volume 15 (1982)
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Volume 14 (1981)
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Volume 13 (1980)
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Volume 12 (1979)
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Volume 11 (1978)
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Volume 10 (1977)
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Volume 9 (1976)
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Volume 8 (1975)
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Volume 7 (1974)
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Volume 6 (1973)
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Volume 5 (1972)
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Volume 4 (1971)
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Volume 3 (1970)
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Volume 2 (1969)
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Volume 1 (1968)