1
|
Patterning and folding of intestinal villi by active mesenchymal dewetting. Cell 2024:S0092-8674(24)00465-3. [PMID: 38781967 DOI: 10.1016/j.cell.2024.04.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/30/2023] [Accepted: 04/26/2024] [Indexed: 05/25/2024]
Abstract
Tissue folds are structural motifs critical to organ function. In the intestine, bending of a flat epithelium into a periodic pattern of folds gives rise to villi, finger-like protrusions that enable nutrient absorption. However, the molecular and mechanical processes driving villus morphogenesis remain unclear. Here, we identify an active mechanical mechanism that simultaneously patterns and folds the intestinal epithelium to initiate villus formation. At the cellular level, we find that PDGFRA+ subepithelial mesenchymal cells generate myosin II-dependent forces sufficient to produce patterned curvature in neighboring tissue interfaces. This symmetry-breaking process requires altered cell and extracellular matrix interactions that are enabled by matrix metalloproteinase-mediated tissue fluidization. Computational models, together with in vitro and in vivo experiments, revealed that these cellular features manifest at the tissue level as differences in interfacial tensions that promote mesenchymal aggregation and interface bending through a process analogous to the active dewetting of a thin liquid film.
Collapse
|
2
|
Patterning and folding of intestinal villi by active mesenchymal dewetting. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.25.546328. [PMID: 37425793 PMCID: PMC10326967 DOI: 10.1101/2023.06.25.546328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Tissue folding generates structural motifs critical to organ function. In the intestine, bending of a flat epithelium into a periodic pattern of folds gives rise to villi, the numerous finger-like protrusions that are essential for nutrient absorption. However, the molecular and mechanical mechanisms driving the initiation and morphogenesis of villi remain a matter of debate. Here, we identify an active mechanical mechanism that simultaneously patterns and folds intestinal villi. We find that PDGFRA+ subepithelial mesenchymal cells generate myosin II-dependent forces sufficient to produce patterned curvature in neighboring tissue interfaces. At the cell-level, this occurs through a process dependent upon matrix metalloproteinase-mediated tissue fluidization and altered cell-ECM adhesion. By combining computational models with in vivo experiments, we reveal these cellular features manifest at the tissue-level as differences in interfacial tensions that promote mesenchymal aggregation and interface bending through a process analogous to the active de-wetting of a thin liquid film.
Collapse
|
3
|
Non-Infectious Complications in B-Lymphopenic Common Variable Immunodeficiency. J Investig Allergol Clin Immunol 2023:0. [PMID: 37103527 DOI: 10.18176/jiaci.0902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
BACKGROUND AND OBJECTIVE Common variable immunodeficiency (CVID) is considered the most symptomatic type of inborn errors of immunity in humans. Along with infectious complications, which have numerous consequences, non-infectious complications are also a major challenge among CVID patients. METHODS All registered CVID patients in the national database were included in this retrospective cohort study. Patients were divided into two groups based on the presence of B-cell lymphopenia. Demographic characteristics, laboratory findings, non-infectious organ involvements, autoimmunity, and lymphoproliferative diseases were evaluated. RESULTS Among 387 enrolled patients, 66.4% were diagnosed with non-infectious complications; however, 33.6% had only infectious presentations. Enteropathy, autoimmunity, and lymphoproliferative disorders were reported in 35.1%, 24.3%, and 21.4% of patients, respectively. Some complications, including autoimmunity and hepatosplenomegaly, were reported to be significantly higher among patients with B-cell lymphopenia. Among organ involvement, dermatologic, endocrine and musculoskeletal systems were predominantly affected in CVID patients with B-cell lymphopenia. Among autoimmune manifestations, the frequency of rheumatologic, hematologic, and gastrointestinal autoimmunity was reported to be higher compared to other types of autoimmunity independent from the B cell-lymphopenia. Furthermore, hematological cancers, particularly lymphoma, were slightly introduced as the most common type of malignancy. Meanwhile, the mortality rate was 24.5%, and respiratory failure and malignancies were reported as the most common cause of death in our patients without significant differences between the two groups. CONCLUSION Considering that some of the non-infectious complications might be associated with B-cell lymphopenia, therefore, regular patient monitoring and follow-up along with proper medications (besides immunoglobulins replacement therapy) are highly recommended to prevent further sequels and increase the patients' quality of life.
Collapse
|
4
|
The spectrum of inborn errors of immunity: a single tertiary center retrospective study in Alborz, Iran. Eur Ann Allergy Clin Immunol 2023; 55:19-28. [PMID: 34918886 DOI: 10.23822/eurannaci.1764-1489.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Summary Background. Inborn errors of immunity (IEIs) are a group of heterogeneous disorders with inherited faults in the immune system that increase susceptibility to infections, malignancies, lymphoproliferation, and autoimmune/autoinflammatory disorders. Methods. We retrospectively studied the demographic characteristics, clinical features, and immunological profiles of the 90 IEIs patients, who were diagnosed and classified according to the European Society for Immunodeficiencies (ESID) and International Union of Immunological Societies (IUIS) criteria from July 2010 to June 2021. The study was carried out in the Non-communicable Diseases Research Center, Imam Ali Hospital, Alborz, Iran. Results. Within a period of 11 years, 53 (58.9%) males and 37 (41.1%) females were diagnosed and followed up for 20 IEI disorders. The median (IQR) age of onset, age of clinical diagnosis and diagnostic delay was 0.7 (0.08-2.0), 3.18 (1.0-8.0) and 1.5 (0.17-5.0) years, respectively. Twelve patients (36.4%) had a positive family history of IEI, and the majority of patients (84.5%) had recurrent infections. Pneumonia (51.7%) was the most common clinical manifestation among IEI patients, followed by skin complications (46.2%). The most frequently diagnosed IEI was immunoglobulin A deficiency (IgAD) (14.4%) and severe combined immunodeficiency (SCID) (11.1%). Predominantly antibody deficiencies group (36.7%) was the most common category, followed by combined immunodeficiencies with associated or syndromic features group (27.8%). Conclusions. IEIs have different patterns within populations with high consanguinity. There is a need to search for underlying genetic and epigenetic factors in most common IEIs in Alborz.
Collapse
|
5
|
Effect of fish oil and canola oil supplementation on immunological parameters, feed intake, and growth of Holstein calves. J Dairy Sci 2022; 105:2509-2520. [PMID: 35033346 DOI: 10.3168/jds.2021-21134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/20/2021] [Indexed: 11/19/2022]
Abstract
Supplemental n-3 fatty acids (FA) may support better immune responses than n-6 and n-9 FA in dairy calves. The objective was to evaluate the effect of n-3 FA, supplemented as a fish oil product (FO) in the milk replacer (MR), in comparison to n-6 and n-9 FA, supplemented as canola oil (CO), on body weight (BW), daily gain, and immunological parameters of preweaning Holstein calves. The study was conducted from September to December 2019. Calves were randomly allocated to a control group (n = 15; BW = 36.2 ± 1.5 kg; mean ± SEM) supplemented daily with 30 mL of CO and to an experimental group (n = 15; BW = 36.3 ± 1.5 kg) supplemented with 60 g of a product containing 30 g of FO. Both treatments were added to the MR during the morning feeding. All calves were fed 4 L of MR at 12.5% solids at 0700 and 1600 h for wk 1, 6 L from wk 2 to 7, and 3 L once daily (0700 h) during wk 8 until weaning (56 d). Blood samples were collected at 7, 14, 21, 28, 35, 42, 49, and 56 d of age for serum haptoglobin, TNF-α, IL-1β, and protectin. Dry matter intake was recorded in all experimental calves daily. Seroneutralization titers to vaccination against viral diseases (infectious bovine rhinotracheitis, parainfluenza 3, bovine viral diarrhea, and bovine respiratory syncytial virus) were determined. Mixed models for repeated measures were developed to analyze variables over time. Seroneutralization titers were analyzed by the Kruskal-Wallis test. The other variables were compared by a generalized linear model. Serum FA profile at 35 d of age showed that FO supported higher concentrations of n-3 FA than CO. Final BW [65.2 vs. 62.0 kg, standard error of the mean (SEM) = 2.1 kg] and average daily gain (0.52 vs. 0.46 kg/d, SEM = 0.1 kg/d) tended to be higher for the FO than the CO group. An interaction of treatment × day for dry matter intake was observed, especially during weaning (2.17 kg vs. 1.94 kg, SEM = 0.158 kg, for FO and CO group, respectively). Blood lactate (mmol/L) was higher in the CO than in the FO group at d 7. Haptoglobin and IL-1β were higher for the CO group on d 14 than the FO group. The TNF- α concentrations for the FO group were reduced over time, whereas the concentrations in the CO group remained constant. Protectin was higher in the FO group on d 14, but was lower on d 28, 35, and 49. Seroneutralization antibody titers postvaccination for the PI3 virus were higher for the FO than the CO group. In conclusion, calves supplemented with FO had lower concentrations of blood lactate, haptoglobin, IL-1β and TNF-α than calves supplemented with CO during the study period. The FO supplementation had a higher DMI than CO supplementation. Results of this trial should be interpreted with caution due to the lack of a negative control group as well as the lower birth weight and growth rate observed under heat stress conditions.
Collapse
|
6
|
228 Sex and Racial Visual Representation in Emergency Medicine Textbooks: A Call to Action to Dismantle the Hidden Curriculum Against Diversity in Medicine. Ann Emerg Med 2021. [DOI: 10.1016/j.annemergmed.2021.09.240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
7
|
123P Impact of the STK11 mutation on the response to immunotherapy. J Thorac Oncol 2021. [DOI: 10.1016/s1556-0864(21)01965-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
8
|
Androgen Signaling Regulates SARS-CoV-2 Receptor Levels and Is Associated with Severe COVID-19 Symptoms in Men. Cell Stem Cell 2020; 27:876-889.e12. [PMID: 33232663 PMCID: PMC7670929 DOI: 10.1016/j.stem.2020.11.009] [Citation(s) in RCA: 139] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/17/2020] [Accepted: 11/13/2020] [Indexed: 01/08/2023]
Abstract
SARS-CoV-2 infection has led to a global health crisis, and yet our understanding of the disease and potential treatment options remains limited. The infection occurs through binding of the virus with angiotensin converting enzyme 2 (ACE2) on the cell membrane. Here, we established a screening strategy to identify drugs that reduce ACE2 levels in human embryonic stem cell (hESC)-derived cardiac cells and lung organoids. Target analysis of hit compounds revealed androgen signaling as a key modulator of ACE2 levels. Treatment with antiandrogenic drugs reduced ACE2 expression and protected hESC-derived lung organoids against SARS-CoV-2 infection. Finally, clinical data on COVID-19 patients demonstrated that prostate diseases, which are linked to elevated androgen, are significant risk factors and that genetic variants that increase androgen levels are associated with higher disease severity. These findings offer insights on the mechanism of disproportionate disease susceptibility in men and identify antiandrogenic drugs as candidate therapeutics for COVID-19.
Collapse
|
9
|
Evaluation of Apoptosis Induction by Newcastle Disease Virus LaSota Strain in Human Breast Carcinoma Cells. ARCHIVES OF RAZI INSTITUTE 2020; 75:367-376. [PMID: 33025777 DOI: 10.22092/ari.2019.125824.1322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/24/2019] [Indexed: 09/30/2022]
Abstract
The innovation of therapeutic modalities with better clinical efficacy is necessary for the treatment of patients with advanced cancers. Newcastle disease virus (NDV), an avian pathogenic virus, is one of the most promising oncolytic viruses that can replicate selectively in human cancer cells. In humans, NDV can cause transient conjunctivitis and mild flu-like symptoms. However, this virus poses no hazard to human health. The elucidation of the mechanisms of cancer cell killing by NDV is helpful for the clinical application of NDV in cancer patients. Regarding this, the present study was performed to evaluate apoptosis induction by NDV LaSota strain vaccine in human breast carcinoma cells. To this end, MCF-7 cells, a human breast adenocarcinoma cell line, were infected with NDV in vitro. Tumor cell cytotoxicity, apoptosis induction, and expression levels of apoptosis-related genes were examined in NDV-infected breast carcinoma cells. Tumor cell cytotoxicity was measured by 3-[4,5-dimethylthiazol-2yl]2,5-diphenyl-tetrazoliumbromide (MTT) assay. The induction of apoptosis was assessed by annexin V/propidium iodide staining. In addition, the expression levels of apoptosis-related genes were evaluated using real-time reverse transcription polymerase chain reaction (PCR) technique. The NDV showed cytotoxic effects on MCF-7 cells and induced apoptosis in the infected carcinoma cells. The gene expression levels of BAX, caspase-9, and caspase-3, but not BAK-1, were increased in NDV-infected cancer cells, compared to the gene expression levels in the non-infected cancer cells. These results suggest that the induction of the intrinsic pathway of apoptosis is one of the mechanisms that can contribute to cancer cell killing by NDV. Additional studies are required to investigate other probable mechanisms involved in NDV-mediated cancer cell killing.
Collapse
|
10
|
Androgen Regulates SARS-CoV-2 Receptor Levels and Is Associated with Severe COVID-19 Symptoms in Men. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.05.12.091082. [PMID: 32511360 PMCID: PMC7263488 DOI: 10.1101/2020.05.12.091082] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has led to a global health crisis, and yet our understanding of the disease pathophysiology and potential treatment options remains limited. SARS-CoV-2 infection occurs through binding and internalization of the viral spike protein to angiotensin converting enzyme 2 (ACE2) on the host cell membrane. Lethal complications are caused by damage and failure of vital organs that express high levels of ACE2, including the lungs, the heart and the kidneys. Here, we established a high-throughput drug screening strategy to identify therapeutic candidates that reduce ACE2 levels in human embryonic stem cell (hESC) derived cardiac cells. Drug target analysis of validated hit compounds, including 5 alpha reductase inhibitors, revealed androgen signaling as a key modulator of ACE2 levels. Treatment with the 5 alpha reductase inhibitor dutasteride reduced ACE2 levels and internalization of recombinant spike receptor binding domain (Spike-RBD) in hESC-derived cardiac cells and human alveolar epithelial cells. Finally, clinical data on coronavirus disease 2019 (COVID-19) patients demonstrated that abnormal androgen states are significantly associated with severe disease complications and cardiac injury as measured by blood troponin T levels. These findings provide important insights on the mechanism of increased disease susceptibility in male COVID-19 patients and identify androgen receptor inhibition as a potential therapeutic strategy.
Collapse
|
11
|
Computational intelligence approaches for classification of medical data: State-of-the-art, future challenges and research directions. Neurocomputing 2018. [DOI: 10.1016/j.neucom.2017.01.126] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
12
|
22 Comparing Three Extenders: Hashi, Green Buffer and INRA 96, for Chilled Storage of Bactrian Camel Semen. Reprod Fertil Dev 2018. [DOI: 10.1071/rdv30n1ab22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Semen preservation remains challenging in the camel industry. The objective of the present study was to compare 3 different extenders for chilled storage of Bactrian camel semen. Semen (n = 9 ejaculates) was collected from camel bulls (n = 2) manually using artificial vagina. Good neat semen, as far as mass vibration concerns, was equally distributed into 3 double-wall vessels filled with 35°C water. The 3 extenders used in the present study were Hashi, Green buffer (IMV, L’Aigle, France), and INRA 96 (IMV). The Hashi extender consisted of Tris, 2.6%; citric acid, 1.35%; glucose, 0.9%; fructose, 0.9%; penicillin G sodium, 1000 IU mL−1; streptomycin sulfate, 1000 mg mL−1 supplemented with 20% plasma egg yolk and 20% camel skim milk; osmolality of 330 and pH of 6.9). Green buffer was supplemented with 20% plasma egg yolk (osmolality of 335 and pH of 6.9). The osmolality and pH of INRA 96 were 310 and 7, respectively. Extenders at a ratio of 1:3 were added to semen followed by pipetting 10 times with an automatic pipettor. The water-jacketed extended specimen was covered with foam and transferred to individual vaccine carrier equipped with 4 ice packs. This system of cooling not only allows the specimen to cool down slowly and reach 4°C after 7 h, but also reduces the viscosity of camel semen. The assessment was carried out 7 and 24 h after semen dilution, when the specimen reached 4°C. Semen viability parameters were assessed after short-term semen preservation in different extenders. Total motility and progressive forward motility were examined subjectively by single operator using Sperm Track (ISAS, Proiser, Spain) after diluting the specimen to achieve 25 × 106 sperm mL−1. Live percentage of sperm was estimated using Eosin B Fast Green staining method. Plasma membrane integrity was assessed using the hypo-osmotic swelling (HOS) test. Following arcsin transformation, data were analysed by GLM procedure followed by Tukey test in SAS (SAS Institute Inc., Cary, NC, USA). At 7 and 24 h, there were no differences among the 3 extenders in total motility of sperm (Hashi: 73 and 67.4%; Green buffer: 71.6 and 62.1%; INRA 96: 70 and 66.2%; P > 0.05), live percentage of sperm (Hashi: 76 and 73%; Green buffer: 70.5 and 65.6%; INRA 96: 77.8 and 70.7%; P > 0.05), or HOS test (Hashi: 52.4 and 45.2%; Green buffer: 49.6 and 40.6%; INRA 96: 57.3 and 51.1%; P > 0.05). However, at the same times, progressive forward motility was similar between Hashi (47.7 and 28.6%) and Green buffer (40 and 23.5%; P > 0.05) but was different between Hashi and INRA 96 (23.6 and 16.7%; P < 0.05). In conclusion, Hashi and Green buffer could be considered suitable extenders to preserve Bactrian camel semen under chilled condition. Further studies with a larger number of bulls and ejaculates are warranted.
Collapse
|
13
|
Évaluation du suivi et du statut nutritionnel après gastric bypass chez 45 patients. NUTR CLIN METAB 2016. [DOI: 10.1016/j.nupar.2016.09.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
14
|
|
15
|
Evaluation of plasma MMP-8, MMP-9 and TIMP-1 identifies candidate cardiometabolic risk marker in metabolic syndrome: results from double-blinded nested case-control study. Metabolism 2015; 64:527-38. [PMID: 25633268 DOI: 10.1016/j.metabol.2014.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 12/11/2014] [Accepted: 12/22/2014] [Indexed: 12/21/2022]
Abstract
AIMS Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are dysregulated in metabolic syndrome (MetS) and associated with atherosclerosis and cardiovascular disease (CVD). Previous studies on the association between MMPs/TIMPs and MetS are controversial. We aimed to evaluate circulating MMP-8, MMP-9 and TIMP-1 in a group of MetS individuals and healthy controls to find the potential marker associated with MetS and its components. METHODS 243 MetS individuals participated in a nested case-control design, of whom 63 were excluded (study subjects for analysis n=180; 87 MetS cases, 93 controls). We employed the International Diabetes Federation criteria using national waist circumference cutoffs for case definition. Anthropometric and biochemical measurements were done using standard methods. RESULTS Plasma MMP-8, TIMP-1, tumor necrosis factor-alpha (TNF-α), highly sensitive C-reactive protein (hs-CRP) and MMP-8/TIMP-1 ratio were significantly higher in MetS cases (P for all < 0.05). Each component of MetS except raised fasting plasma glucose positively correlated with MMP-8 and numbers of MetS components increased with higher MMP-8. In all regression models, MMP-8 was a significant predictor of MetS and in the final model the relationship persisted even after adjusting for pro-inflammatory cytokines hs-CRP and TNF-α (odds ratio=6.008, 95% confidence interval: 1.612-22.389, P=0.008). CONCLUSION Strong associations of MMP-8 with components of MetS in univariate, bivariate and multivariate models suggest plasma MMP-8 as a potential cardiometabolic risk marker for MetS. Higher MMP-8 in MetS is possibly mediated through mechanisms both dependent and independent of chronic low grade inflammation.
Collapse
|
16
|
Semen collection using phantom in dromedary camel. Anim Reprod Sci 2014; 151:15-21. [DOI: 10.1016/j.anireprosci.2014.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/13/2014] [Accepted: 09/16/2014] [Indexed: 11/25/2022]
|
17
|
Molecular characterization, genetic diversity and antibacterial susceptibility of Escherichia coli encoding Shiga toxin 2f in domestic pigeons. Lett Appl Microbiol 2014; 59:370-6. [PMID: 24863542 DOI: 10.1111/lam.12288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 05/20/2014] [Accepted: 05/20/2014] [Indexed: 12/01/2022]
Abstract
This study aimed to evaluate prevalence, characteristics, genotypic diversity and antibacterial susceptibility of Escherichia coli encoding Shiga toxin 2f in domestic pigeons in different provinces of Iran. A total of 117 faecal samples were collected from pigeons and were subjected to molecular detection of stx2f. In total, 20, 25·8, 21·4 and 9% of pigeons from Tehran, Ferdows, Garmsar and Babol cities carried stx2f+ isolates, respectively. Of the 460 E. coli isolates examined, 43 were stx2f+ and most also carried eae (95·3%) and astA (97·7%) genes. Some of the stx2f+ isolates harboured cnf (9·3%), but all were negative for stx1, stx2 (other subtypes) and ehly. Most Strains (90%) were assigned to B1 phylogroup and possessed Intimin-β. Fingerprinting of the stx2f+ isolates using either enterobacterial repetitive intergenic consensus sequences (ERIC) or random amplified polymorphic DNA (RAPD)-polymerase chain reaction revealed seven distinct profiles by each method, with one prevailing (65·1 and 46·5%, respectively). By the combination of methods, 10 profiles were recognized. Ten isolates from different profiles were shown to belong to O20, O78 and O115 serogroups, and eight were 100% identical in the stx2f gene sequence. The strains were consistently resistant to amoxicillin and lincospectin and commonly resistant to tetracycline (88·4%) and doxycycline (74·4%). Overall, the results indicate a limited degree of genetic diversity in stx2f-harbouring E. coli from pigeons. Significance and impact of the study: Carriage of stx2f gene tends to be underreported in pigeon Escherichia coli isolates because most routine genetic and phenotypic tests cannot efficiently target this gene or detect the toxin. Nevertheless, pigeons frequently carry E. coli strains that are stx2f-positive, and this situation is not limited to any distinct geographical area. The current results suggest that genetic background of stx2f-encoding E. coli is distinct from most Shiga toxin-producing E. coli strains. However, the factors that contribute to host preferences and pathogenicity remain unclear. These findings have public health significance that should be addressed in future research.
Collapse
|
18
|
Vitamin D3 inhibits inflammatory cascade in endometrial cells through down regulation of TLR signaling. J Reprod Immunol 2012. [DOI: 10.1016/j.jri.2012.03.432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
19
|
Microbial profiles of on-line--procured sprouting seeds and potential hazards associated with enterotoxigenic Bacillus spp. in homegrown sprouts. J Food Prot 2005; 68:1648-53. [PMID: 21132973 DOI: 10.4315/0362-028x-68.8.1648] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We examined the microbiological quality of sprouting seeds sold through the Internet. Overall, five types of seeds each from six organic and six conventional sources were evaluated. The growth and toxin production of naturally occurring Bacillus spp. in sprouts produced using home-scale sprouting devices also were investigated. For alfalfa, broccoli, lentil, mungbean, and radish seeds, the average microbial counts were 3.3, 4.0, 2.8, 3.5, and 3.6 log CFU/g, presumptive B. cereus counts were 0.7, 1.0, 0.8, 1.0, and 0.9 log CFU/g, and total coliform counts were -0.3, -0.4, -0.5, 0.0, and -0.4 log of the most probable number per gram, respectively. No Salmonella, Escherichia coli O157, other fecal coliforms, or Staphylococcus aureus was found on seeds. Compared with conventional seeds, the organic seeds had lower or equivalent counts for total microorganisms, presumptive B. cereus, and total coliforms. When seeds were sprouting using a glass jar, the growth of presumptive B. cereus was significant for radish and broccoli but not for alfalfa, lentil, and mungbean sprouts; the counts exceeded 5.0 log CFU/g in radish sprouts. When sprouts were grown using an automatic sprouting device, presumptive B. cereus showed slight growth (< 3.0 log cycles) in radish, broccoli, and mungbean sprouts but no growth in alfalfa and lentil sprouts. Although the presumptive B. cereus isolates were enterotoxigenic, they did not produce or accumulate detectable levels of diarrheal toxins in freshly produced sprouts.
Collapse
|
20
|
Changes in the microflora of commercial soft goat milk cheese during refrigerated and frozen-storage. Small Rumin Res 2004. [DOI: 10.1016/j.smallrumres.2003.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|