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Darier disease (DD) is a rare autosomal dominant genodermatosis characterized by erythematous papules and plaques mainly involving sebaceous areas, such as the face, chest and back. Skin microbiome plays an essential role in maintaining skin homeostasis. A disturbed skin microbiome may contribute to the exacerbation of DD. We investigated the bacterial composition of two predilectional sites in DD patients and healthy individuals. We also measured the microbiome composition of deeper skin layers, where diversity was significantly reduced compared to the superficial layer of the skin from the same area. The microbiome of DD patients at lesional sites differed from that of non-lesional skin areas; moreover, non-lesional sites were different from those of the controls. Lesional areas were dominated by Staphylococcus species, such as S. aureus , S. epidermidis , S. hominis , S. sciuri , and S. equorum . However, levels of Cutibacterium acnes (formerly Propionibacterium acnes) and C. acnes subspecies defendens were significantly lower in lesional sites than in non-lesional sites. A significant decrease was measured in the levels of these two bacteria between non-lesional and control samples. Our findings may indicate that alterations in the skin microbiome could contribute to the inflammation of skin lesions in DD.

Ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. The cattle tick, Rhipicephalus (Boophilus) microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. Tick microbiomes remain largely unexplored. The objective of this study was to explore the R. microplus microbiome by applying the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) technique to characterize its bacterial diversity. Pyrosequencing was performed on adult males and females, eggs, and gut and ovary tissues from adult females derived from samples of R. microplus collected during outbreaks in southern Texas. Raw data from bTEFAP were screened and trimmed based upon quality scores and binned into individual sample collections. Bacteria identified to the species level include Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus sciuri, Serratia marcescens, Corynebacterium glutamicum, and Finegoldia magna. One hundred twenty-one bacterial genera were detected in all the life stages and tissues sampled. The total number of genera identified by tick sample comprised: 53 in adult males, 61 in adult females, 11 in gut tissue, 7 in ovarian tissue, and 54 in the eggs. Notable genera detected in the cattle tick include Wolbachia, Coxiella, and Borrelia. The molecular approach applied in this study allowed us to assess the relative abundance of the microbiota associated with R. microplus. This report represents the first survey of the bacteriome in the cattle tick using non-culture based molecular approaches. Comparisons of our results with previous bacterial surveys provide an indication of geographic variation in the assemblages of bacteria associated with R. microplus. Additional reports on the identification of new bacterial species maintained in nature by R. microplus that may be pathogenic to its vertebrate hosts are expected as our understanding of its microbiota expands. Increased awareness of the role R. microplus can play in the transmission of pathogenic bacteria will enhance our ability to mitigate its economic impact on animal agriculture globally. This recognition should be included as part of analyses to assess the risk for re-invasion of areas like the United States of America where R. microplus was eradicated.

The mucosal adjuvant activity of cholera toxin depends on the microbiota, which signals through Nod2 on CD11c + cells. Cholera toxin (CT) is a potent adjuvant for inducing mucosal immune responses. However, the mechanism by which CT induces adjuvant activity remains unclear. Here we show that the microbiota is critical for inducing antigen-specific IgG production after intranasal immunization. After mucosal vaccination with CT, both antibiotic-treated and germ-free (GF) mice had reduced amounts of antigen-specific IgG, smaller recall-stimulated cytokine responses, impaired follicular helper T (T FH ) cell responses and reduced numbers of plasma cells. Recognition of symbiotic bacteria via the nucleotide-binding oligomerization domain containing 2 (Nod2) sensor in cells that express the integrin CD11c (encoded by Itgax ) was required for the adjuvanticity of CT. Reconstitution of GF mice with a Nod2 agonist or monocolonization with Staphylococcus sciuri , which has high Nod2-stimulatory activity, was sufficient to promote robust CT adjuvant activity, whereas bacteria with low Nod2-stimulatory activity did not. Mechanistically, CT enhanced Nod2-mediated cytokine production in dendritic cells via intracellular cyclic AMP. These results show a role for the microbiota and the intracellular receptor Nod2 in promoting the mucosal adjuvant activity of CT.

The aim of this cross-sectional study was to evaluate the prevalence of subclinical mastitis (SCM) and associated risk factors in dairy cows in peri-urban areas of Kigali, Rwanda, and identify causative udder pathogens. A sample of 256 cows from 25 herds was screened with the California Mastitis Test (CMT), and udder quarters with CMT score ≥ 3 (scale 1–5) were milk sampled for culture and final bacteriological identification with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). All resultant staphylococci species were tested for beta-lactamase production with the clover leaf method. In parallel, herd bulk milk somatic cell count (SCC) of each herd was analysed using a portable device, the DeLaval cell counter. The prevalence of SCM was 43.1% at quarter level and 76.2% at cow level based on CMT test. Multiparous, Holstein cows were 2.50 (C.I = 1.32–4.71) and 10.08 (C.I = 1.54–66.13) times more likely to contract SCM infection than primiparous animals or cows of other breeds, respectively. The median and mean SCC of all herds were 1108 × 103 cells/mL and 1179 × 103 cells/mL, respectively. The most prevalent pathogens were non-aureus staphylococci (NAS; 40.2%) followed by Staphylococcus aureus (22%) and less prevalent pathogens (6%). Samples with no growth or contamination constituted 30.4% and 1.4% of the diagnoses, respectively. The most prevalent species within NAS were S. epidermidis (38.2%) followed by S. sciuri (19.5%), S. chromogenes (9.8%), and nine less prevalent NAS species (32.5%). Out of 209 staphylococci isolates, 77% exhibited beta-lactamase production. The study shows that there is high prevalence of SCM and high herd bulk milk SCC in herds in Kigali, indicating udder health problems in dairy cows. Additionally, beta-lactamase production among staphylococci species was common. Improved milking hygiene and application of biosecurity measures, or a complete mastitis control plan, is required to lower the prevalence of SCM and minimize the spread of pathogens among dairy cows.

We investigated antibiotic resistance of staphylococci isolated from 1128 samples of high-circulating RTE foods in Taiwan. A total of 111 Staphylococcus aureus and 709 coagulase-negative staphylococci (CoNS) comprising 23 species were isolated. The prevalence of S. aureus differed in various category of RTE foods, highest in fresh-cut fruits/vegetables (20.5%) and lowest in low-water activity (LWA) foods (0.7%). The overall staphylococcal contamination was highest in fresh-cut fruits/vegetables (62.2%), in which multiple isolates (up to 10) or species (up to 6) in single sample were frequently found. Distinct distribution of species contributed to unique feature in each category. Prevalence of antibiotic-resistant S. aureus was higher in fresh-cut fruits/vegetables samples (14.2% in 127) compared to other food categories (0–7.1%). A total of 4 MRSA carrying SCCmec type IV or VT were identified (3.6% in 111), in which 3 belonged to sequence type ST59 and one was ST5. Among CoNS, S. epidermidis and S. warneri exhibited higher non-intrinsic antibiotic resistance than other species. Of 41 methicillin-resistant CoNS (5.8% in 709) isolates, SCCmec type IV (n = 16) and type VT (n = 6) were most frequent. Isolates of S. saprophyticus, S. xylosus and S. sciuri displayed high rates of resistance to fusidic acid. Novel fusB-family determinants were identified in S. xylosus, S. sciuri and S. kloosii, which may contribute to their intrinsic resistance to fusidic acid. Compared to other food categories, fresh-cut fruits/vegetables were more contaminated by staphylococci carrying non-intrinsic resistance determinants including methicillin resistance. This nation-wide study demonstrated that some categories may have potential risk for transmitting antibiotic resistance, in which S. epidermidis and S. warneri should be gotten more attention. [Display omitted] •Each RTE food category had unique pattern of staphylococcal contamination.•Novel fusB-family determinants were identified in Staphylococcus xylosus, Staphylococcus sciuri and Staphylococcus kloosii.•Fresh-cut fruits/vegetables were more contaminated by staphylococci carrying non-intrinsic resistance determinants.

Bacteriocins are antimicrobial peptides produced by bacteria. This study aimed to in silico analyze the presence of bacteriocin gene clusters (BGCs) among the genomes of 22 commensal Staphylococcus isolates from different origins (environment/human/food/pet/wild animals) previously identified as bacteriocin producers. The resistome and plasmidome were studied in all isolates. Five types of BGC were detected in 18 genomes of the 22 bacteriocin-producing staphylococci included in this study: class I (Lanthipeptides), class II, circular bacteriocins, the non-ribosomal-peptide lugdunin and the thiopeptide micrococcin P1 (MP1). A high frequency of lanthipeptides was detected in this collection: BGC variants of BSA, bacCH91, and epilancin15X were identified in two Staphylococcus aureus and one Staphylococcus warneri isolates from food and wild animals. Moreover, two potentially new lanthipeptide-like BGCs with no identity to database entries were found in Staphylococcus epidermidis and Staphylococcus simulans from food and wild animal, respectively. Interestingly, four isolates (one S. aureus and one Staphylococcus hominis , environmental origin; two Staphylococcus sciuri , food) carried the MP1 BGC with differences to those previously described. On the other hand, seven of the 22 genomes (~32%) lacked known genes related with antibiotic or disinfectant-acquired resistance mechanisms. Moreover, the potential carriage of plasmids was evaluated, and several Rep-proteins were identified (~73% of strains). In conclusion, a wide variety of BGCs has been observed among the 22 genomes, and an interesting relationship between related Staphylococcus species and the type of bacteriocin has been revealed. Therefore, bacteriocin-producing Staphylococcus and especially coagulase-negative staphylococci (CoNS) can be considered good candidates as a source of novel bacteriocins.

Aphids are one of the most serious pests of crops worldwide, causing major yield and economic losses. To control aphids, natural enemies could be an option but their efficacy is sometimes limited by their dispersal in natural environment. Here we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri , which acts as a kairomone enhancing the efficiency of aphid natural enemies. Our findings represent the first case of a host-associated bacterium driving prey location and ovipositional preference for the natural enemy. We show that this bacterium has a key role in tritrophic interactions because it is the direct source of volatiles used to locate prey. Some specific semiochemicals produced by S. sciuri were also identified as significant attractants and ovipositional stimulants. The use of this host-associated bacterium could certainly provide a novel approach to control aphids in field and greenhouse systems. In this study, a bacterium is identified in the honeydew of aphids, which produces volatile chemicals and attracts hoverflies. The findings could aid the development of pest control systems for aphids.

Some social arthropods engage in mutualistic symbiosis with antimicrobial compound-producing microorganisms that provide protection against pathogens. Social spiders live in communal nests and contain specific endosymbionts with unknown function. Bacteria are also found on the spiders’ surface, including prevalent staphylococci, which may have protective potential. Here we present the genomic and phenotypic characterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 as novel strain of Staphylococcus sciuri within subgroup 2 of three newly defined genomic subgroups. Further phenotypic investigations showed that S. sciuri i1 is an extremophile that can grow at a broad range of temperatures (4 °C–45 °C), high salt concentrations (up to 27%), and has antimicrobial activity against closely related species. We identified a lactococcin 972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity, and found it conserved in two of the three subgroups of S. sciuri. These features indicate that S. sciuri i1, though not a specific symbiont, is well-adapted to survive on the surface of social spiders and may gain a competitive advantage by inhibiting closely related species.

Abstract A β-carbonic anhydrase (CA, EC 4.2.1.1) previously annotated to be present in the genome of Staphylococcus aureus, SauBCA, has been shown to belong to another pathogenic bacterium, Mammaliicoccus (Staphylococcus) sciuri. This enzyme, MscCA, has been investigated for its activation with a series of natural and synthetic amino acid and amines, comparing the results with those obtained for the ortholog enzyme from Escherichia coli, EcoCAβ. The best MscCA activators were D-His, L- and D-DOPA, 4-(2-aminoethyl)-morpholine and L-Asn, which showed KAs of 0.12 − 0.89 µM. The least efficient activators were D-Tyr and L-Gln (KAs of 13.9 − 28.6 µM). The enzyme was also also inhibited by anions and sulphonamides, as described earlier. Endogenous CA activators may play a role in bacterial virulence and colonisation of the host which makes this research topic of great interest.

Bovine mastitis is an important disease in dairy cows, and Staphylococcus aureus is the most prevalent microorganism. Bacteriophages are considered an alternative to treat bacterial infections due to antimicrobial resistance crisis. In this study, we isolated and characterized novel S. aureus temperate phages, namely B_UFSM4 and B_UFSM5, from bovine milk. The complete genomes of B_UFSM4 and B_UFSM5 have 41.396 bp and 41.829 bp, respectively. The viruses have double-stranded DNA and linear architecture. Phylogenic similarity was observed by proteome with Staphylococcus phage phiPV83, CN125 and JS01. Therefore, the phages were classified into the family Siphoviridae, genus Biseptimavirus and order Caudovirales. In the host range, the B_UFSM4 and B_UFSM5 had lytic activity of 45.8% and 54.16%, respectively, inclusive on isolates from Staphylococcus sciuri and Rothia terrae. Thus, in this study, species novel of S. aureus temperate phages was isolated and characterized, these phages reveal similarities to each other; however, they are distinct from other species of S. aureus phages of the family Siphoviridae.