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Journal of Dairy Science Jul 2017Non-aureus staphylococci (NAS), the microorganisms most frequently isolated from bovine milk worldwide, are a heterogeneous group of numerous species. To establish their...
Non-aureus staphylococci (NAS), the microorganisms most frequently isolated from bovine milk worldwide, are a heterogeneous group of numerous species. To establish their importance as a group, the distribution of individual species needs to be determined. In the present study, NAS intramammary infection (IMI) was defined as a milk sample containing ≥1,000 cfu/mL in pure or mixed culture that was obtained from a cohort of cows assembled by the Canadian Bovine Mastitis Research Network. Overall, 6,213 (6.3%) of 98,233 quarter-milk samples from 5,149 cows and 20,305 udder quarters were associated with an NAS IMI. Of the 6,213 phenotypically identified NAS isolates, 5,509 (89%) were stored by the Canadian Bovine Mastitis Research Network Mastitis Pathogen Collection and characterized using partial sequencing of the rpoB housekeeping gene, confirming 5,434 isolates as NAS. Prevalence of each NAS species IMI was estimated using Bayesian models, with presence of a specific NAS species as the outcome. Overall quarter-level NAS IMI prevalence was 26%. The most prevalent species causing IMI were Staphylococcus chromogenes (13%), Staphylococcus simulans (4%), Staphylococcus haemolyticus (3%), Staphylococcus xylosus (2%), and Staphylococcus epidermidis (1%). The prevalence of NAS IMI as a group was highest in first-parity heifers and was evenly distributed throughout cows in parities ≥2. The IMI prevalence of some species such as S. chromogenes, S. simulans, and S. epidermidis differed among parities. Overall prevalence of NAS IMI was 35% at calving, decreased over the next 10 d, and then gradually increased until the end of lactation. The prevalence of S. chromogenes, Staphylococcus gallinarum, Staphylococcus cohnii, and Staphylococcus capitis was highest at calving, whereas the prevalence of S. chromogenes, S. haemolyticus, S. xylosus, and S. cohnii increased during lactation. Although the overall prevalence of NAS IMI was similar across barn types, the prevalence of S. simulans, S. xylosus, S. cohnii, Staphylococcus saprophyticus, S. capitis, and Staphylococcus arlettae IMI was higher in tiestall barns; the prevalence of S. epidermidis IMI was lowest; and the prevalence of S. chromogenes and Staphylococcus sciuri IMI was highest in bedded-pack barns. Staphylococcus simulans, S. epidermidis, S. xylosus, and S. cohnii IMI were more prevalent in herds with intermediate to high bulk milk somatic cell count (BMSCC) and S. haemolyticus IMI was more prevalent in herds with high BMSCC, whereas other common NAS species IMI were equally prevalent in all 3 BMSCC categories. Distribution of NAS species IMI differed among the 4 regions of Canada. In conclusion, distribution differed considerably among NAS species IMI; therefore, accurate identification (species level) is essential for studying NAS epidemiology.
Topics: Animals; Bayes Theorem; Canada; Cattle; Cattle Diseases; Female; Mammary Glands, Animal; Mastitis, Bovine; Milk; Pregnancy; Prevalence; Species Specificity; Staphylococcal Infections; Staphylococcus
PubMed: 28527793
DOI: 10.3168/jds.2016-12478 -
Applied and Environmental Microbiology May 2021A pervasive pest of stored leguminous products, the bean beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) associates with a simple bacterial community during...
A pervasive pest of stored leguminous products, the bean beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) associates with a simple bacterial community during adulthood. Despite its economic importance, little is known about the compositional stability, heritability, localization, and metabolic potential of the bacterial symbionts of C. maculatus. In this study, we applied community profiling using 16S rRNA gene sequencing to reveal a highly conserved bacterial assembly shared between larvae and adults. Dominated by and , this community is localized extracellularly along the epithelial lining of the bean beetle's digestive tract. Our analysis revealed that only one species, Staphylococcus gallinarum (phylum ), is shared across all developmental stages. Isolation and whole-genome sequencing of S. gallinarum from the beetle gut yielded a circular chromosome (2.8 Mb) and one plasmid (45 kb). The strain encodes complete biosynthetic pathways for the production of B vitamins and amino acids, including tyrosine, which is increasingly recognized as an important symbiont-supplemented precursor for cuticle biosynthesis in beetles. A carbohydrate-active enzyme search revealed that the genome codes for a number of digestive enzymes, reflecting the nutritional ecology of . The ontogenic conservation of the gut microbiota in the bean beetle, featuring a "core" community composed of , may be indicative of an adaptive role for the host. In clarifying symbiont localization and metabolic potential, we further our understanding and study of a costly pest of stored products. From supplementing essential nutrients to detoxifying plant secondary metabolites and insecticides, bacterial symbionts are a key source of adaptations for herbivorous insect pests. Despite the pervasiveness and geographical range of the bean beetle , the role of microbial symbioses in its natural history remains understudied. Here, we demonstrate that the bean beetle harbors a simple gut bacterial community that is stable throughout development. This community localizes along the insect's digestive tract and is largely dominated by Staphylococcus gallinarum. In elucidating symbiont metabolic potential, we highlight its possible adaptive significance for a widespread agricultural pest.
Topics: Animals; Coleoptera; Female; Gastrointestinal Microbiome; Genome, Bacterial; Genomics; Larva; Male; Ovum; Staphylococcus; Symbiosis
PubMed: 33863703
DOI: 10.1128/AEM.00212-21 -
Pathogens (Basel, Switzerland) Apr 2024A novel coagulase-negative strain (H164) was isolated from soymilk in Taiwan. Comparative sequence analysis of the 16S rRNA gene revealed that the H164 strain is a...
A novel coagulase-negative strain (H164) was isolated from soymilk in Taiwan. Comparative sequence analysis of the 16S rRNA gene revealed that the H164 strain is a member of the genus . We used multilocus sequence analysis (MLSA) and phylogenomic analyses to demonstrate that the novel strain was closely related to , , , and . The average nucleotide identity and digital DNA-DNA hybridization values between H164 and its closest relatives were <95% and <70%, respectively. The H164 strain could also be distinguished from its closest relatives by the fermentation of -fructose, -maltose, -trehalose, and -mannitol, as well as by the activities of α-glucosidase and alkaline phosphatase. The major cellular fatty acids were C15:0 iso and C15:0 anteiso, and the predominant menaquinones were MK-7 and MK-8, respectively. The major cellular fatty acids and predominant menaquinones were C iso and C anteiso and MK-7 and MK-8, respectively. In conclusion, this strain represents a novel species, named sp. nov., with the type strain H164 (=BCRC 81404 = NBRC 116174).
PubMed: 38668298
DOI: 10.3390/pathogens13040343 -
Brazilian Journal of Microbiology :... Dec 2022This research aimed to identify the diversity of bacterial species of the genus Staphylococcus spp. in subclinical mastitis in dairy herds in the state of Piauí,...
This research aimed to identify the diversity of bacterial species of the genus Staphylococcus spp. in subclinical mastitis in dairy herds in the state of Piauí, Northeastern Brazil, and to evaluate the phenotypic and genotypic resistance profile. Samples were obtained from a total of 17 dairy farms, amounting to 321 positive samples in the California Mastitis Test. Staphylococcus spp. were identified by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy. Subsequently, an antibiogram was performed, and a polymerase chain reaction was carried out to screen for resistance genes in the isolates. Among all the isolates, 59.45% (110/185) belonged to the Staphylococcus genus. Moreover, the following Staphylococcus spp. were identified Staphylococcus aureus, 68.1% (75/110); Staphylococcus chromogenes, 12.7% (14/110); Staphylococcus epidermidis, 5.4% (6/110); Staphylococcus sciuri, 4.5% (5/110); Staphylococcus warneri, 2.7% (3/110); Staphylococcus haemolyticus, 1.8% (2/110); Staphylococcus hominis, 1.8% (2/110); Staphylococcus arlettae, 0.9% (1/110); Staphylococcus capitis, 0.9% (1/110); and Staphylococcus gallinarum, 0.9% (1/110). The antibiogram showed a high frequency of resistance to penicillin and ampicillin, 70.0% (77/110) and 61.8% (68/110), respectively, and a low frequency of resistance to gentamicin and vancomycin, 10.9% (12/110) and 11.8% (13/110), respectively. In the genotypic tests for the different species of Staphylococcus spp., the occurrence of the blaZ gene was observed in 60.9% (67/110) of the isolates, followed by tetL and tetM, both with 20.0% (22/110) each, and the mecA and vanB genes were detected in 0.9% (1/110) of the samples. The identification of all Staphylococcus species isolated from subclinical mastitis cases and the phenotypic and genotypic resistance characterization in these isolates is of great importance for dairy farming in the state of Piauí, as well as for public health.
Topics: Cattle; Animals; Female; Humans; Mastitis, Bovine; Methicillin-Resistant Staphylococcus aureus; Brazil; Staphylococcus; Staphylococcal Infections; Microbial Sensitivity Tests; Milk; Anti-Bacterial Agents
PubMed: 36074251
DOI: 10.1007/s42770-022-00822-1 -
BMJ Case Reports Aug 2019A rare case of endophthalmitis with intraocular foreign body (IOFB) was managed successfully by vitrectomy, IOFB removal and intravitreal antibiotics with steroids....
A rare case of endophthalmitis with intraocular foreign body (IOFB) was managed successfully by vitrectomy, IOFB removal and intravitreal antibiotics with steroids. Intraoperatively, the inferior retina was noted to be pale, possibly secondary to arteriolar occlusion/inflammation. This pale retina detached while peeling the vitreous, but spontaneously reattached postoperatively within a week. The case report describes the natural course of an iatrogenic detachment of pallid retina and the outcome of an uncommon ocular infection.
Topics: Accidents, Occupational; Adult; Anti-Bacterial Agents; Endophthalmitis; Eye Foreign Bodies; Eye Infections, Bacterial; Eye Injuries, Penetrating; Humans; Male; Retinal Detachment; Treatment Outcome; Visual Acuity; Vitrectomy
PubMed: 31434672
DOI: 10.1136/bcr-2019-230126 -
Food Science & Nutrition Aug 2022Broad bean fermentation is of vital importance in PixianDouban (PXDB) production, as well as a key process for microorganisms to degrade protein, which lays the...
UNLABELLED
Broad bean fermentation is of vital importance in PixianDouban (PXDB) production, as well as a key process for microorganisms to degrade protein, which lays the foundation for the formation of PXDB flavor. In this study, two fungi and bacteria were screened, and their morphology, molecular biology, growth, and enzyme production characteristics were analyzed, and then they were applied to the broad bean fermentation simulation system. The protein, peptide, amino acid, amino nitrogen, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system were evaluated. The results showed that the four microorganisms were , , , and . had the highest protease activity at pH 7.0, while the other three strains had better enzyme activity stability under neutral acidic conditions. And the total protein (F1 and F2 were 18.32 g/100 g, 19.15 g/100 g, respectively), peptides (11.79 ± 0.04 mg/g and 12.06 ± 0.04 mg/g), and amino acids (55.12 ± 2.78 mg/g and 54.11 ± 1.97 mg/g) of the fungus experimental groups (F) were higher than the bacterial experimental groups (B). In addition, the enzyme system produced by fungi exhibited a stronger ability for albumin (20 kDa) and glutenin (<30 kDa) deterioration in neutral conditions, while the bacterial enzyme system was more efficient in degrading albumin (<30 kDa) and glutenin (20-30 kDa) in acidic conditions, as indicated by SDS-PAGE. These findings showed that both bacteria and fungi played an important role in the degradation of protein in different fermentation stages of broad bean fermentation.
PRACTICAL APPLICATIONS
There is a lack of comprehensive understanding of the protein composition and protein degradation mechanism of broad beans in the fermentation stage of PXDB. This research work explored the differences in the degradation of PXDB fermented protein by different microorganisms, and provided a theoretical basis for optimizing the production of PXDB and improving the quality of PXDB.
PubMed: 35959259
DOI: 10.1002/fsn3.2879 -
ELife Nov 2016Some bacteria use lactic acid to communicate with yeast cells.
Some bacteria use lactic acid to communicate with yeast cells.
Topics: Bacteria; Dekkera; Ethanol; Glucose; Prions; Saccharomyces cerevisiae
PubMed: 27897124
DOI: 10.7554/eLife.22256 -
Toxicology Reports 2021Toombak is a smokeless tobacco produced from the tobacco plant from Sudan. Pre-prepared and ready to buy Toombak samples were analysed using mass spectrometry (heavy...
Toombak is a smokeless tobacco produced from the tobacco plant from Sudan. Pre-prepared and ready to buy Toombak samples were analysed using mass spectrometry (heavy metals), gas and liquid chromatography (metabolomics), 16S rRNA metagenomic sequencing (microbiome) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and pH analysis. Chromium, cobalt, and copper were high in the pre-prepared form of Toombak while iron, tobacco specific nitrosamines (TSNAs), formaldehyde and acetaldehyde were high in both types. and dominated Toombak. Samples of ready to buy Toombak showed inter-variational differences depending on place of purchase. We found were increased in the pre-prepared form while and were the most abundant species in the ready to buy forms. PICRUSt analysis highlighted increased activity of metal transport systems in the ready to buy samples as well as an antibiotic transport system. SEM-EDX highlighted large non-homogenous, irregular particles with increased sodium, while pH of samples was in the alkaline range. The final composition of Toombak is affected by its method of preparation and the end product has the potential to impart many negative consequences on the health of its users. TSNA levels observed in Toombak were some of the highest in the world while the micro-environment of Toombak supports a distinct microbiota profile.
PubMed: 34401360
DOI: 10.1016/j.toxrep.2021.07.008 -
Journal of Dairy Science Jun 2018A commercial blue-veined cheese made from unpasteurized milk was examined by conventional culturing and PCR denaturing gradient gel electrophoresis analysis of the...
A commercial blue-veined cheese made from unpasteurized milk was examined by conventional culturing and PCR denaturing gradient gel electrophoresis analysis of the bacterial community 16S rRNA genes using 3 primer sets, V3, V4V5, and V6V8. Genomic DNA for amplification was extracted directly from raw milk, starter culture, cheese at different stages of production, fully ripened cheese, and from the cultured cells grown on various media. The outer rind was sampled separately from the inner white core and blue veins. A diverse microbiota containing Lactococcus lactis ssp. lactis, Lactobacillus plantarum, Lactobacillus curvatus, Staphylococcus gallinarum, Staphylococcus devriesei, Microbacterium sp., Sphingobacterium sp., Mycetocola sp., Brevundimonas sp., Enterococcus faecalis, Proteus sp., and Kocuria sp. was detected in the raw milk using culturing methods, but only Lactococcus lactis ssp. lactis, Lactobacillus plantarum, and Enterococcus faecalis survived to the final cheese and were detected both in the core and the rind. Using PCR denaturing gradient gel electrophoresis analysis of the cheese process samples, Staphylococcus equorum and Enterococcus durans were found in the rind of prepiercing samples but not in the core and veins; after piercing, these species were found in all parts of the cheese but survived only in the rind when the cheese was fully ripened. Brevibacterium sp., Halomonas sp., Acinetobacter sp., Alkalibacterium sp., and Corynebacterium casei were identified only by PCR denaturing gradient gel electrophoresis and not cultured from the samples. Brevibacterium sp. was initially identified in the cheese postpiercing (core and veins), Halomonas sp. was found in the matured cheese (rind), and Acinetobacter sp., Alkalibacterium sp., and Corynebacterium casei were also found in the prepiercing samples (rind) and then found through the subsequent process stages. The work suggests that in this raw milk cheese, a limited community from the milk survive to the final cheese, with salt addition and handling contributing to the final cheese consortium.
Topics: Animals; Bacteria; Biodiversity; Cheese; Colony Count, Microbial; DNA, Bacterial; Denaturing Gradient Gel Electrophoresis; Food Microbiology; Microbiota; Milk; Polymerase Chain Reaction; RNA, Ribosomal, 16S; United Kingdom
PubMed: 29550118
DOI: 10.3168/jds.2017-14104 -
Applied and Environmental Microbiology Jun 2020Humans have used high salinity for the production of bean-based fermented foods over thousands of years. Although high salinity can inhibit the growth of harmful...
Humans have used high salinity for the production of bean-based fermented foods over thousands of years. Although high salinity can inhibit the growth of harmful microbes and select functional microbiota in an open environment, it also affects fermentation efficiency of bean-based fermented foods and has a negative impact on people's health. Therefore, it is imperative to develop novel defined starter cultures for reduced-salt fermentation in a sterile environment. Here, we explored the microbial assembly and function in the fermentation of traditional Chinese broad bean paste with 12% salinity. The results revealed that the salinity and microbial interactions together drove the dynamic of community and pointed out that five dominant genera (, , , , and ) may play different key roles in different fermentation stages. Then, core species were isolated from broad bean paste, and their salinity tolerance, interactions, and metabolic characteristics were evaluated. The results provided an opportunity to validate predictions through dissection of microbial assembly and function. Last, we reconstructed the synthetic microbial community with five strains (, , , , and ) under different salinities and realized efficient fermentation of broad bean paste for 6 weeks in a sterile environment with 6% salinity. In general, this work provided a bottom-up approach for the development of a simplified microbial community model with desired functions to improve the fermentation efficiency of bean-based fermented foods by deconstructing and reconstructing the microbial structure and function. Humans have mastered high-salinity fermentation techniques for bean-based fermented product preparation over thousands of years. High salinity was used to select the functional microbiota and conducted food fermentation production with unique flavor. Although a high-salinity environment is beneficial for suppressing harmful microbes in the open fermentation environment, the fermentation efficiency of functional microbes is partially inhibited. Therefore, application of defined starter cultures for reduced-salt fermentation in a sterile environment is an alternative approach to improve the fermentation efficiency of bean-based fermented foods and guide the transformation of traditional industry. However, the assembly and function of self-organized microbiota in an open fermentation environment are still unclear. This study provides a comprehensive understanding of microbial function and the mechanism of community succession in a high-salinity environment during the fermentation of broad bean paste so as to reconstruct the microbial community and realize efficient fermentation of broad bean paste in a sterile environment.
Topics: Bacterial Physiological Phenomena; Fermentation; Food Microbiology; Fungi; Microbiota; Models, Biological; Salinity; Vicia faba
PubMed: 32303548
DOI: 10.1128/AEM.00306-20