Fusobacterium nucleatum and Bacteroides fragilis detection in colorectal tumours: Optimal target site and correlation with total bacterial load

Background Mucosal infiltration by certain bacterial species may contribute to the development and progression of colorectal cancer (CRC). There is considerable variation in reported detection rates in human CRC samples and the extent to which bacterial infiltration varies across regions of the primary tumour is unknown. This study aimed to determine if there is an optimal site for bacterial detection within CRC tumours. Methods Presence of target bacterial species was assessed by quantitative real-time PCR (qPCR) in 42 human CRC tumours. Abundance in primary tumour regions, normal epithelium and at metastatic sites was investigated in an expanded cohort of 51 patients. Species presence/absence was confirmed by diversity profiling in five patients. Correlation with total bacterial load and clinicopathological features was assessed. Results Fusobacterium nucleatum and Bacteroides fragilis were detected in tumours from 43% and 24% of patients, respectively (17% positive for both species). The optimal detection site was the tumour luminal surface (TLS). Patients testing positive at the TLS frequently tested negative at other sites, including central tumour and invasive margin. F. nucleatum was detected at a higher frequency in tumour versus normal epithelium (p < 0.01) and was associated with more advanced disease (p = 0.01). Detection of both species correlated with total bacterial load. However, corroboration of qPCR results via diversity profiling suggests detection of these species may indicate a specific microbial signature. Conclusions This study supports a role for F. nucleatum in CRC development. Presence of F. nucleatum and B. fragilis varies across primary tumour regions, with the TLS representing the optimal site for bacterial detection.

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Association between colorectal cancer and Fusobacterium nucleatum and Bacteroides fragilis bacteria in Iranian patients: a preliminary study

Infectious Agents and Cancer ◽

10.1186/s13027-021-00381-4 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Aref Shariati ◽

Shabnam Razavi ◽

Ehsanollah Ghaznavi-Rad ◽

Behnaz Jahanbin ◽

Abolfazl Akbari ◽

...

Keyword(s):

Colorectal Cancer ◽

Relative Abundance ◽

Normal Tissue ◽

Bacteroides Fragilis ◽

Fusobacterium Nucleatum ◽

Normal Mucosa ◽

Clinicopathologic Characteristics ◽

Tissue Samples ◽

Adjacent Normal Mucosa ◽

Iranian Patients

Abstract Background and aim Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied. Method To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed. Results In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60% of paired tumor and normal samples, respectively. Furthermore, 15% of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23% of tumors and 13% of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2-ΔCT was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes. Conclusion The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown.

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Effectiveness of 0.66% Povidone-Iodine Eye Drops on Ocular Surface Flora before Cataract Surgery: A Nationwide Microbiological Study

Journal of Clinical Medicine ◽

10.3390/jcm10102198 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2198

Author(s):

Rosario Musumeci ◽

Pasquale Troiano ◽

Marianna Martinelli ◽

Matteo Piovella ◽

Claudio Carbonara ◽

...

Keyword(s):

Cataract Surgery ◽

Ocular Surface ◽

Povidone Iodine ◽

Bacterial Species ◽

Bacterial Flora ◽

Bacterial Load ◽

Controlled Study ◽

Eye Drops ◽

Microbiological Analysis ◽

Contralateral Eye

A multicenter, nonrandomized, prospective, controlled study was conducted to evaluate, as perioperative prophylactic treatment, the anti-infective effectiveness of 0.66% povidone-iodine eye drops (IODIM®) against the bacterial flora of the conjunctival surface of patients who undergo cataract surgery. Eye drops containing 0.66% povidone-iodine were applied to the eye undergoing cataract surgery; the untreated contralateral eye was used as control. One hundred and twenty patients set to receive unilateral cataract surgery were enrolled in 5 Italian Ophthalmology Centers and pretreated for three days with 0.66% povidone-iodine eye drops. The contralateral eye, used as control, was left untreated. Conjunctival swabs of both eyes were collected at the baseline visit and after three days of treatment, just before the cataract surgery. A qualitative and quantitative microbiological analysis of bacterial presence was evaluated by means of bacterial culture, followed by identification. Methicillin resistance determination was also performed on staphylococci isolates. Bacterial load before and after treatment of the eye candidate for cataract surgery was evaluated and compared to the untreated eye. A reduction or no regrowth on the culture media of the bacterial load was observed in 100% of the study subjects. A great heterogenicity of bacterial species was found. The 0.66% povidone-iodine eye drops, used for three days prior to cataract surgery, were effective in reducing the conjunctival bacterial load. The 0.66% povidone-iodine eye drops (IODIM®) might represent a valid perioperative prophylactic antiseptic adjuvant treatment to protect the ocular surface from microbial contamination in preparation of the surgical procedure.

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Volatile scents of influenza A and S. pyogenes (co-)infected cells

Scientific Reports ◽

10.1038/s41598-019-55334-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Selina Traxler ◽

Gina Barkowsky ◽

Radost Saß ◽

Ann-Christin Klemenz ◽

Nadja Patenge ◽

...

Keyword(s):

Influenza A ◽

Early Recognition ◽

Bacterial Species ◽

Bacterial Load ◽

Gas Chromatography Mass Spectrometry ◽

Sampling System ◽

Infected Cells ◽

Infection Processes ◽

Non Destructive

AbstractInfluenza A is a serious pathogen itself, but often leads to dangerous co-infections in combination with bacterial species such as Streptococcus pyogenes. In comparison to classical biochemical methods, analysis of volatile organic compounds (VOCs) in headspace above cultures can enable destruction free monitoring of metabolic processes in vitro. Thus, volatile biomarkers emitted from biological cell cultures and pathogens could serve for monitoring of infection processes in vitro. In this study we analysed VOCs from headspace above (co)-infected human cells by using a customized sampling system. For investigating the influenza A mono-infection and the viral-bacterial co-infection in vitro, we analysed VOCs from Detroit cells inoculated with influenza A virus and S. pyogenes by means of needle-trap micro-extraction (NTME) and gas chromatography mass spectrometry (GC-MS). Besides the determination of microbiological data such as cell count, cytokines, virus load and bacterial load, emissions from cell medium, uninfected cells and bacteria mono-infected cells were analysed. Significant differences in emitted VOC concentrations were identified between non-infected and infected cells. After inoculation with S. pyogenes, bacterial infection was mirrored by increased emissions of acetaldehyde and propanal. N-propyl acetate was linked to viral infection. Non-destructive monitoring of infections by means of VOC analysis may open a new window for infection research and clinical applications. VOC analysis could enable early recognition of pathogen presence and in-depth understanding of their etiopathology.

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Spatial and Temporal Features of the Growth of a Bacterial Species Colonizing the Zebrafish Gut

mBio ◽

10.1128/mbio.01751-14 ◽

2014 ◽

Vol 5 (6) ◽

Cited By ~ 62

Author(s):

Matthew Jemielita ◽

Michael J. Taormina ◽

Adam R. Burns ◽

Jennifer S. Hampton ◽

Annah S. Rolig ◽

...

Keyword(s):

Fluorescence Microscopy ◽

Spatial Structure ◽

Growth Kinetics ◽

Spatial Organization ◽

Temporal Dynamics ◽

Bacterial Species ◽

Bacterial Load ◽

Light Sheet ◽

Logistic Growth ◽

Light Sheet Fluorescence Microscopy

ABSTRACTThe vertebrate intestine is home to microbial ecosystems that play key roles in host development and health. Little is known about the spatial and temporal dynamics of these microbial communities, limiting our understanding of fundamental properties, such as their mechanisms of growth, propagation, and persistence. To address this, we inoculated initially germ-free zebrafish larvae with fluorescently labeled strains of anAeromonasspecies, representing an abundant genus in the zebrafish gut. Using light sheet fluorescence microscopy to obtain three-dimensional images spanning the gut, we quantified the entire bacterial load, as founding populations grew from tens to tens of thousands of cells over several hours. The data yield the first ever measurements of the growth kinetics of a microbial species inside a live vertebrate intestine and show dynamics that robustly fit a logistic growth model. Intriguingly, bacteria were nonuniformly distributed throughout the gut, and bacterial aggregates showed considerably higher growth rates than did discrete individuals. The form of aggregate growth indicates intrinsically higher division rates for clustered bacteria, rather than surface-mediated agglomeration onto clusters. Thus, the spatial organization of gut bacteria both relative to the host and to each other impacts overall growth kinetics, suggesting that spatial characterizations will be an important input to predictive models of host-associated microbial community assembly.IMPORTANCEOur intestines are home to vast numbers of microbes that influence many aspects of health and disease. Though we now know a great deal about the constituents of the gut microbiota, we understand very little about their spatial structure and temporal dynamics in humans or in any animal: how microbial populations establish themselves, grow, fluctuate, and persist. To address this, we made use of a model organism, the zebrafish, and a new optical imaging technique, light sheet fluorescence microscopy, to visualize for the first time the colonization of a live, vertebrate gut by specific bacteria with sufficient resolution to quantify the population over a range from a few individuals to tens of thousands of bacterial cells. Our results provide unprecedented measures of bacterial growth kinetics and also show the influence of spatial structure on bacterial populations, which can be revealed only by direct imaging.

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Metagenome of SARS-Cov2 patients in Shenzhen with travel to Wuhan shows a wide range of species - Lautropia, Cutibacterium, Haemophilus being most abundant - and Campylobacter explaining diarrhea

10.31219/osf.io/jegwq ◽

2020 ◽

Cited By ~ 7

Author(s):

Sandeep Chakraborty

Keyword(s):

Secondary Infection ◽

Bacterial Species ◽

Bacterial Load ◽

San Diego County ◽

Opportunistic Pathogens ◽

Sequencing Data ◽

Familial Cluster ◽

Chinese Study ◽

Wide Range ◽

Initial Results

The metagenome of patients infected with SARS-Cov2 [1] has shown Prevotella to be a key player in immune response [2] in one Chinese study [3], just starting in another [4] and a host of other opportunistic pathogens in a study from San Diego county [5]. The metagenome can also be queried to find host response genes [5], as was done in monkey cells infected with SARS-Cov2 [6]Nanopore sequencing data from a familial cluster in ShenzhenThe patients were tested for 4 bacterial species - Bordetella pertussis, Bordetella parapertussis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. The sequencing data (Accid:SRR10948474, Nanopore) from five patients in a family cluster from Shenzhen who presented with unexplained pneumonia after returning from Wuhan (Table 1) shows a wide range of bacterial species - Lautropia, Cutibacterium, Haemophilus being most abundant. The presence of Campylobacter explains diarrhea seen in the patient [7,8]. Also, their tests should have detected Mycoplasma, since it is there in the data.Significant bacterial load with some bacterial species predominatingThe bacterial reads are about 20% (95K out of 500K reads). The viral load is also significant here (70K reads) [2]. They are in SI.familial/allsequences.fa. The number of bacterial species (with at least two reads) is 876 (SI.familial/list.allbacteria.txt). Thus, it is important to consider secondary infection, a possible reason why azithromycin (in addition to hydroxychloroquine) has given good initial results in a clinical trial [9].

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Characterization of the Subgingival Cultivable Microbiota in Patients with Different Stages of Periodontitis in Spain and Colombia. A Cross-Sectional Study

Microorganisms ◽

10.3390/microorganisms9091940 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1940

Author(s):

Roquelina Pianeta ◽

Margarita Iniesta ◽

Diana Marcela Castillo ◽

Gloria I. Lafaurie ◽

Mariano Sanz ◽

...

Keyword(s):

Bacterial Species ◽

Fusobacterium Nucleatum ◽

Cross Sectional Study ◽

Sectional Study ◽

Chi Square ◽

Cross Sectional ◽

Campylobacter Rectus ◽

Parvimonas Micra ◽

Final Sample

The objective was to characterize and compare the subgingival microbiota in patients diagnosed according to the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions 2018. For this cross-sectional study, Spanish and Colombian subjects (characterized as health/gingivitis, periodontitis in stages I-II or stages III-IV) were clinically assessed, and subgingival samples were taken and processed by culture. The comparisons among patients with periodontal status (and between countries) was made using Mann–Whitney, Kruskal–Wallis, ANOVA and chi-square tests. The final sample consisted of 167 subjects. Eikenella corrodens and Parvimonas micra were more frequently detected in health/gingivitis and Porphyromonas gingivalis in periodontitis (p < 0.05). Higher total counts were observed in Colombia (p = 0.036). In Spain, significantly higher levels of P. gingivalis and Campylobacter rectus were observed, and of Tannerella forsythia, P. micra, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus and Capnocytophaga spp. in Colombia (p < 0.001). P. micra was more prevalent in health/gingivitis and stage I-II periodontitis in Colombia, and P. gingivalis in all periodontitis groups in Spain (p < 0.05). As conclusions, significant differences were detected in the microbiota between health/gingivitis and periodontitis, with minor differences between stages of periodontitis. Differences were also relevant between countries, with Colombia showing larger counts and variability of bacterial species.

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Fusobacterium nucleatum Infection of Colonic Cells Stimulates MUC2 Mucin and Tumor Necrosis Factor Alpha

Infection and Immunity ◽

10.1128/iai.05118-11 ◽

2011 ◽

Vol 79 (7) ◽

pp. 2597-2607 ◽

Cited By ~ 59

Author(s):

Poonam Dharmani ◽

Jaclyn Strauss ◽

Christian Ambrose ◽

Emma Allen-Vercoe ◽

Kris Chadee

Keyword(s):

Tumor Necrosis ◽

Bacterial Species ◽

Fusobacterium Nucleatum ◽

Mucin Secretion ◽

Necrosis Factor Alpha ◽

Content Type ◽

Tnf Α ◽

Factor Alpha ◽

Colonic Cells ◽

Necrosis Factor

ABSTRACTThe etiology of inflammatory bowel disease is not completely known, but it is influenced by the presence of normal gut microflora as well as yet-unrecognized pathogens. The anaerobic, Gram-negative bacterial speciesFusobacterium nucleatumis a common resident of the human mouth and gut and varies in its pathogenic potential. In this study, we demonstrate that highly invasiveF. nucleatumisolates derived from the inflamed guts of Crohn's disease patients evoked significantly greater MUC2 and tumor necrosis factor alpha (TNF-α) gene expression than minimally invasive strains isolated from the noninflamed gut in human colonic epithelial cells and in a rat ligated colonic loop model of infection. Only liveF. nucleatuminduced mucin secretion and TNF-α expression in direct contact with and/or during invasion of colonic cells. In rat colons, mucin secretion was augmented in response to a highly invasiveF. nucleatumisolate but was unaffected by treatment with a minimally invasive strain. Taken together, these studies reveal thatF. nucleatummay represent a challenging pathogen in the etiology of gut inflammatory diseases and highlight the importance of different pathotypes of candidate bacterial species in disease pathogenesis.

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Inoperable stage IV colorectal cancer with intact primary tumor in patients receiving palliative chemotherapy: Does the response to chemotherapy correlate between primary and metastatic sites? An Irish cancer center experience.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.3_suppl.136 ◽

2021 ◽

Vol 39 (3_suppl) ◽

pp. 136-136

Author(s):

Ruba Hamed ◽

Ronan Andrew McLaughlin ◽

Hatim Ibrahim ◽

Greg Korpanty ◽

Nemer Osman

Keyword(s):

Stable Disease ◽

Primary Tumour ◽

Stage Iv ◽

Primary Site ◽

First Line ◽

Tumour Site ◽

Response To Chemotherapy ◽

Stage 4 ◽

Metastatic Sites ◽

Line Chemotherapy

136 Background: Colorectal cancer (CRC) is the 3rd most common malignancy in Ireland with over 2700 cases annually. Approximately 20% are diagnosed with stage IV disease. The aim of this study is to evaluate the response to chemotherapy at primary and metastatic sites and review the frequency of intervention required to palliate the intact primary tumour in patients with stage 4 inoperable CRC in an Irish tertiary referral centre. Methods: A retrospective review of medical records was completed, identifying stage 4 CRC patients with primary tumour in situ diagnosed between January 2014 and December 2019, treated with chemotherapy (oxaliplatin or irinotecan based +/- bevacizumab or EGFR monoclonal antibody). Data and survival analysis were obtained using Kaplan-Meier methods. Results: 50 eligible patients were identified; 60% male, 40% female with a median age of 62 years. 2% had a transverse colonic primary, 32% right and 44% left sided and 22% had a rectal primary. 36% presented with liver metastasis only, 4% lung metastasis alone and 20% both. 48% were KRAS, 4% NRAS and 4% BRAF mutation positive while 1 patient was identified as having microsatellite instability. All patient received first-line chemotherapy either oxaliplatin or irinotecan based, 18% with the addition of Bevacizumab and 24% with EGFR monoclonal antibody. Overall response to first-line chemotherapy at the primary site and metastatic sites was assessed radiologically; 42% displaying a partial response, 36% had stable disease while 18% had progression at primary site. At the metastatic sites 50% responded, 10% stable disease and 40% progressed. Complication at primary tumour site included: obstruction 12%, with perforation in 6%, bleeding 10%, pain at tumour site in 6%, and one patient developed an abscess. Overall, after chemotherapy 76% of all patients did not require further intervention to manage primary site. 6% underwent curative surgery with resection of primary and metastatic lesions. Of those who had palliative intervention; 10% underwent palliative colostomy/ileostomy, 12% palliative radiotherapy, and 2% both. Overall survival was 14 months. At time of analysis 14% were alive, 10% receiving treatment and 4% on radiological surveillance. Conclusions: This retrospective study confirms that palliative chemotherapy +/- targeted therapy is effective in controlling the primary tumour in stage 4 inoperable CRC. In addition, it reveals a nearly 80% partial response or stable disease radiologically at the primary site after first-line chemotherapy. Furthermore, progression was significantly lower at primary site compared to distant metastasis (18% vs 40%). Almost 75% did not require palliative intervention for their primary tumour. Overall survival in our centre is higher compared to internationally observed data.

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