Applied microbiology最新文献

{"title":"High-Throughput Viability Testing of Microbial Communities in a Probiotic Product Using Flow Cytometry","authors":"Joanna V. Pereira, Hasinika K. A. H. Gamage, Amy K. Cain, Evan Hayes, Ian T. Paulsen, Sasha G. Tetu","doi":"10.3390/applmicrobiol3030074","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030074","url":null,"abstract":"There is growing scientific and commercial interest in multi-species probiotic products due to their potential benefits in maintaining gut health. Determining the viability of probiotic microorganisms in these products is essential to ensure that they confer maximal health benefits. The gold standard for enumerating probiotic viability is the plate count method. However, this may be inaccurate for enumerating mixed probiotic populations, with recognised limitations including difficulty measuring metabolically active yet unculturable, very slow growing microbes, microencapsulated, enteric coated microbes, or multi-strain formulations that require differing growth media. Here, we developed a flow-cytometry-based approach using SYTOXTM Green dye to assess the viability of probiotic microorganisms in a multi-species, fibre-containing probiotic product and compared this to the traditional plate count method. This method was suitable for enumerating both total bacterial cells and the viable cell fraction in the complete product mixture, and could also be used to assess how stressors, such as gastric digestion and exposure to bile acids, affect bacterial cell viability. Flow cytometry measurements routinely detected higher viable cell counts than plate counting. This work demonstrates that flow cytometry assays can be established as a suitable method for rapid enumeration of viable cells in complex, multi-species probiotics.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"364 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135938387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Salmonella Enteritidis ST11 Prosthetic Valve Endocarditis Complicated by a Paravalvular Abscess: Case Report and Literature Review","authors":"Shiori Kitaya, S. Katahira, Hiroaki Baba, Y. Saiki, Yukio Katori, K. Tokuda, Hajime Kanamori","doi":"10.3390/applmicrobiol3030073","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030073","url":null,"abstract":"Salmonella infection typically causes self-limiting gastroenteritis. However, in rare cases, it can lead to prosthetic valve endocarditis (PVE), especially in older adults with a history of valve replacement surgery. In this case study, we describe a case of Salmonella PVE in a man with a prosthetic aortic valve. Complications of PVE include abscess formation, which is associated with increased mortality. If a patient with a history of prosthetic valve replacement presents with symptoms suggestive of gastroenteritis or bacteremia, a thorough investigation should be conducted with suspicion of PVE. The prognosis of Salmonella PVE can be improved by promptly initiating appropriate antibiotics and administering them for an adequate duration, as well as by considering surgical intervention when necessary. Additionally, confirming negative blood cultures after treatment of Salmonella bacteremia is important to prevent the development of PVE and paravalvular abscesses.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79948682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diabetic Foot Osteomyelitis Caused by Co-Infection with Methicillin-Resistant Staphylococcus aureus and Multidrug-Resistant Extended-Spectrum ß-Lactamase-Producing Escherichia coli: A Case Report","authors":"Shiori Kitaya, Chieko Miura, Ayano Suzuki, Yoshimichi Imai, K. Tokuda, Hajime Kanamori","doi":"10.3390/applmicrobiol3030072","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030072","url":null,"abstract":"This case report describes a 47-year-old man with type 2 diabetes and its associated complications. The patient developed co-infection with methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli following surgical amputation for osteomyelitis caused by diabetic foot infection (DFI). The patient had a history of recurrent hospitalization due to DFI and had received multiple antimicrobials. Intraoperative wound cultures identified MRSA and MDR ESBL-producing E. coli as the causative agents of the co-infection. Intravenous vancomycin and meropenem were administered. After surgery, daily debridement and hyperbaric oxygen therapy were performed. The patient underwent surgical wound closure and was discharged on day 86. Polymicrobial infections in DFIs worsen antimicrobial resistance, impede wound healing, and increase the risk of osteomyelitis and amputation. Furthermore, infections caused by MDR bacteria exacerbate challenges in infection control, clinical treatment, and patient outcomes. In DFI cases caused by co-infection with MDR bacteria, prompt and appropriate antimicrobial therapy, debridement, and regular wound care while considering transmission are essential.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"162 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80990756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Two Bacterial Characterization Techniques for the Genomic Analysis of River Microbiomes","authors":"Roberto Bonnelly, V. V. Calderon, Irene Ortiz, Argeny Ovando, Confesora Pinales, Willy Lara, Santo E. Mateo-Perez, Oscar Cardenas-Alegria, Rommel T. Ramos, Yaset Rodríguez-Rodríguez, Luis O. Maroto Martín, Edian F. Franco","doi":"10.3390/applmicrobiol3030071","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030071","url":null,"abstract":"This study compares the feasibility of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry with whole genome sequencing (WGS) for identifying bacteria in river surface water samples. We collected samples from four rivers in the Dominican Republic and used both techniques to characterize bacterial profiles. MALDI-TOF demonstrated high precision, with 86.2% similarity to WGS results, except for a few discordant cases due to database limitations. MALDI-TOF provided cost-effective and rapid identification, making it a promising alternative to WGS in resource-constrained regions. In particular, good effectiveness of MALDI-TOF in identifying bacteria with a high probability of being resistant to antibiotics was observed, which allows this technology to be used in the monitoring processes of this type of microorganism for their rapid, accurate, and low-cost identification. We found this technology to be advantageous for environmental bacterial profiling, with potential applications in understanding waterborne pathogenic bacteria. Our findings underline the relevance of MALDI-TOF in microbiology and its potential to expand its capabilities in bacterial identification and protein profiling.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83733847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population Dynamics in the Biogenesis of Single-/Multi-Layered Membrane Vesicles Revealed by Encapsulated GFP-Monitoring Analysis","authors":"Sangho Koh, Shuhei Noda, Seiichi Taguchi","doi":"10.3390/applmicrobiol3030070","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030070","url":null,"abstract":"Various generations of membrane vesicles (MV) have been observed in Escherichia coli in terms of triggering events and populations of single-layered (s)/multi-layered (m) forms. Previously, we proposed a novel mechanism for MV generation triggered by the intracellular accumulation of biopolyester polyhydroxybutyrate (PHB). This was designated as the Polymer Intracellular Accumulation-triggered system for Membrane Vesicle Production (PIA-MVP). Herein, we attempted to determine the conditions for the change in the population between s-MV and m-MV using glucose concentration-dependent PIA-MVP. PIA-MVP was established using the good correlation between the glucose concentration-dependent PHB accumulation and MV generation. Thus, we assumed the presence of a critical glucose concentration could determine the population ratio of s-MV to m-MV, indicating that s-MV generation is a dominant component in the extracellular environment. Cytoplasmic green fluorescent protein (GFP) was used to evaluate the glucose concentration, enabling the selective generation of s-MV. The glucose concentration was determined to be 15 g/L to satisfy this purpose under the culture conditions. In conclusion, we established a biological system allowing us to selectively generate both single- and multi-layered MVs based on PIA-VIP encapsulation of GFP, providing a versatile toolkit to gain insights into the MV generation mechanism and achieve progress in various engineering applications.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82101442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Safety and Effects of Intravaginal Administration of Lacticaseibacillus rhamnosus CRL1332 Immobilized on Nanofibers in a Murine Experimental Model","authors":"J. A. Silva, P. R. De Gregorio, M. E. Nader-Macías","doi":"10.3390/applmicrobiol3030069","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030069","url":null,"abstract":"The design of probiotic hygiene products for daily use is considered an adequate alternative for the restoration of the vaginal microbiome, maintaining health, and/or preventing infections of the female urogenital tract. Most of these probiotic products are available on the world market, but their efficacy and safety are not sufficiently documented. One of the requirements to transfer novel probiotic formulas/products to the productive sector is to demonstrate their innocuity and the absence of adverse or collateral effects on the host, mainly assayed in experimental models. The inclusion of beneficial lactobacilli in nanofibers by electrospinning technique has shown promising application possibilities, and the immobilization of Lacticaseibacillus rhamnosus CRL1332 in nanofibers with and without bioprotective substances and their characterization were previously performed by our research group. In this work, the safety of the intravaginal (i.va.) administration of these functional nanofibers in a murine experimental model was evaluated. L. rhamnosus CRL1332 immobilized in different nanofibers was intravaginally inoculated into mice (seven daily doses). Vaginal washes were taken for microbiological (cultivable lactobacilli) and cytological techniques, and the vagina was used for histological and morphological-ultrastructural evaluation. Our results demonstrated that the intravaginal administration of L. rhamnosus CRL1332 immobilized in nanofibers is safe in murine models, given the absence of an inflammatory response at the cytological and histological levels, with minor modifications at the ultrastructural level, and also related to the normal cultivable vaginal microbiota. On the other hand, the number of cultivable lactobacilli increased in the vagina of mice receiving L. rhamnosus CRL1332 nanofibers. The results indicate the safety of lactobacilli-functional nanofibers and support their inclusion in the design of vaginal probiotic products to prevent/treat urogenital infections and reconstitute the women’s vaginal microbiota.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"5081 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82484263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Potential Role of Fecal Microbiota Transplantation in Parkinson’s Disease: A Systematic Literature Review","authors":"Tahne Vongsavath, T. Laeeq, K. Tun, Annie S. Hong","doi":"10.3390/applmicrobiol3030067","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030067","url":null,"abstract":"Background and Aims: Parkinson’s disease (PD) is a multifaceted disease that can cause symptoms in multiple body systems, including the gastrointestinal (GI) tract. Fecal microbiota transplantation (FMT) is a proposed treatment to address dysregulation in the microbiome, with neurologic and GI symptoms as theoretic effects. The complex relationship between gut dysbiosis and PD symptoms suggests that FMT may have a role in therapy. Methods: A total of 124 articles with information pertaining to PD and FMT were reviewed. PD adult patients with neuromotor or GI symptoms who received FMT with moderate levels of evidence were examined. Data using self-reporting symptom scales were compared at baseline and following FMT. Results: An overall improvement was seen in patients’ neuromotor or GI symptoms, when compared to the baseline after FMT. After FMT, the patients reported improved constipation and decreased time to stool. Overall satisfaction differed between groups receiving differing routes of FMT administration and the severity of their baseline symptoms. Conclusions: FMT shows promising utility for PD patients with neuromotor and/or GI symptoms. Our results are limited by need to evaluate routes of administration, the chronicity of inflammation, and acidity’s role in colonization and efficacy. FMT has been illustrated as a well-tolerated non-pharmacologic treatment method for PD with refractory symptoms.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80705625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Change in the Bacteria Cultured and Isolated in Respiratory Sputum from Elderly Patients during the SARS-CoV-2 Pandemic","authors":"Masayuki Nagasawa, Tomoyuki Kato, Ippei Tanaka, E. Ono","doi":"10.3390/applmicrobiol3030068","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030068","url":null,"abstract":"The SARS-CoV-2 pandemic has affected social patterns and consequently the prevalence of infections, such as seasonal influenza. It has been reported that invasive pneumococcal infection has markedly decreased worldwide. Method: We retrospectively investigated the bacteria cultured and isolated from 23,052 respiratory sputum samples obtained at our hospital from April 2015 to March 2022. The average patient age was 71.8 years old, with a standard deviation of 16.0 years old. There was no significant difference in the age of the patients or the female-to-male ratio between each year. The detection ratio of bacteria was analyzed in accordance with sputum quality based on the Geckler classification. Results: The detection ratio of community-acquired pneumonia pathogens such as Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae increased in parallel with the quality of the sputum, while that of hospital-acquired pneumonia pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus was not significantly affected by the quality of the sputum. The detection ratio of former pathogens in the good-quality respiratory sputum had decreased significantly since April 2020 by 60–80%, while that of P. aeruginosa and S. aureus had increased by 40–50%. Conclusions: The SARS-CoV-2 pandemic reduced the detection ratio of H. influenzae, M. catarrhalis, and S. pneumoniae but increased that of P. aeruginosa and S. aureus in the good-quality respiratory sputum from elderly patients. The influence of this selective change in isolated bacteria on the health and comorbidity of elderly patients remains to be investigated.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84531262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a Chicken Gastrointestinal Tract (GIT) Simulation Model: Impact of Cecal Inoculum Storage Preservation Conditions","authors":"N. M. de Carvalho, Célia Maria Costa, Cláudia Castro, M. Saleh, M. Pintado, D. Oliveira, A. Madureira","doi":"10.3390/applmicrobiol3030066","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030066","url":null,"abstract":"A chicken gastrointestinal tract (GIT) simulation model was developed to help predict the potential effects of feed additives supplementation on chicken’ microbiota. The chemical and enzymatic conditions for oral, gastric, intestinal, and cecum fermentation phases were designed to closely resemble the chicken GIT conditions. For cecum fermentation, the inoculum was obtained from the cecal contents of 18 38-day broiler chickens. The impact of inoculum preservation on bacteria viability was assessed by comparing two methods of preservation with fresh inoculum: (1) 5% dimethyl sulfoxide (DMSO) at −80 °C and (2) 30% glycerol at −20 °C. The fermentation with fresh and frozen (DMSO method) inoculums was performed and compared using standard chicken feed (SCF) and SCF with 1% fructooligosaccharides (FOS), and inoculum control (IC) condition without feed matrix was used as a baseline. Inoculum’s viability was assessed throughout 90 days of storage by culture media platting, while bacterial growth and metabolites production during fermentation was evaluated by quantitative polymerase chain reaction (qPCR), high-performance liquid chromatography (HPLC), and total ammonia nitrogen quantification. The DMSO method was shown to be the most suitable for cecal inoculum storage. Higher growth of beneficial cecal bacteria for fresh inoculum was observed in SCF while for frozen inoculum, was the SCF + FOS condition. Also, frozen inoculum had lower activity of butyrate producers and proteolytic bacteria, showing different fermentation profiles. The GIT model developed showed to be useful to test the effect of feed additives supplementation.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88936168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screening of Rhizobacterial Isolates from Apple Rhizosphere for Their Biocontrol and Plant Growth Promotion Activity","authors":"Salma Jabiri, Ikram Legrifi, Majda Benhammou, Salah-Eddine Laasli, F. Mokrini, M. B. Amraoui, R. Lahlali","doi":"10.3390/applmicrobiol3030065","DOIUrl":"https://doi.org/10.3390/applmicrobiol3030065","url":null,"abstract":"Apple crops are prone to several diseases that limit their production—in particular, root rot caused by a new genus of oomycetes, mainly Phytopythium vexans. This study aims to screen antagonistic bacteria that can play an important role in the biological control of this pathogenic oomycete and to evaluate their capacity to promote plant growth. The dual culture test revealed that, out of 200 bacterial isolates, 16 have been able to inhibit the mycelial growth of P. vexans with inhibition rates greater than 50%. The selected isolates were identified based on the 16S rDNA genes: 14 bacteria belonging to the genus Bacillus, Stenotrophomonas, and the family Enterobacteriaceae. Notably, two isolates, B1 and M2-6 (identified as Bacillus velezensis), demonstrated the highest inhibition rates of 70% and 68%, respectively. These selected isolates were examined for their ability to produce different compounds related to biocontrol and plant growth promotion. Furthermore, the 16 selected isolates were evaluated for their ability to produce compounds associated with biocontrol and plant growth promotion, including hydrolytic enzymes (cellulases, proteases, and amylases), HCN (hydrogen cyanide) production, phosphate solubilization, IAA (indole-3-acetic acid) production, pectinase production, and stimulation of sorghum bicolor growth in vivo. Variations were observed among the bacterial isolates in terms of their compound production and phytostimulation capabilities. However, the secretion of proteases was consistently detected in all antagonistic isolates. The presence of genes responsible for the production of antifungal lipopeptides (bacillomycin, fengycin, and iturin) in the selected bacterial isolates was determined using polymerase chain reaction (PCR) techniques, while the absence of genes involved in surfactin biosynthesis was also confirmed through PCR studies. These isolates demonstrated inhibitory activity through the production of proteases and antifungal lipopeptides. Further research is needed to explore their potential use in biological control strategies and to improve apple crop productivity.","PeriodicalId":8080,"journal":{"name":"Applied microbiology","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80824529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}