Staphylococcus pseudintermedius is an opportunistic pathogen in dogs. Four housekeeping genes with allelic polymorphisms were identified and used to develop an expanded multilocus sequence typing (MLST) scheme. The new seven-locus technique shows S. pseudintermedius to have greater genetic diversity than previous methods and discriminates more isolates based upon host origin.

Staphylococcus pseudintermedius is the primary cause of canine pyoderma and has been associated with diseases in other animals, including human beings. A high prevalence of methicillin and multidrug resistance has been reported in this bacterium in some geographic regions of the United States. Multilocus sequence type (MLST) 68 was implicated, initially, as the major clonal genotype based on a limited number of samples. The objectives of this study were to determine the population genetics of S. pseudintermedius isolated from a cross-section of the United States using a seven-locus multilocus sequence typing method, to identify clonal complexes (CCs), and to correlate sequence types with antimicrobial susceptibility profiles. A total of 190 S. pseudintermedius with 86 different MLSTs were detected and the constituents of three major CCs of methicillin-resistant S. pseudintermedius (MRSP), CC68, CC71, and CC84, were identified. Different patterns of resistance were associated with each CC. CC71 from the United States had notable differences with CC71 studied on other continents with chloramphenicol, tetracycline, and trimethoprim/sulfamethoxazole resistance. Some isolates with resistance to the broadest range of drugs tested, including that to chloramphenicol, had STs unrelated to the major CCs, suggesting the potential for the emergence of new clonal populations of MRSP that are resistant to most therapeutically useful antimicrobials.

Marine invertebrates-associated microorganisms were considered to be important sources of marine bioactive products. This study aims to isolate marine invertebrates associated bacteria with antimicrobial activity from the Red Sea and test their biosynthetic potential through the detection of PKS and NRPS gene clusters involved with the production of bioactive secondary metabolites. In this respect, fifty bacterial strains were isolated from eight different Red Sea marine invertebrates and screened for their antimicrobial activity against standard pathogenic bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633) and yeast (Candida albicans ATCC 10231) using the standard well diffusion assay. Five isolates showed antifungal activity against Candida albicans with no activity recorded against other pathogenic bacterial strains. On the other hand when these isolates were screened for the presence of biosynthetic gene clusters (PKS and NRPS) by PCR using five sets of degenerative primers, 60% of the isolates were shown to contain at least one type of PKS and NRPS gene clusters, which indicates the biosynthetic potential of these isolates even if the isolates didn't express any biological activity in vitro. Moreover the 16S rRNA molecular identification of the isolates reveal the biodiversity of the red sea marine invertebrates associated bacteria as they were found to belong to several bacterial groups present in Alphaproteobacteria, Gammaproteobacteria, Actinobacteria and Firmicutes.

Atopic dermatitis (AD) is a complex, multifactorial, chronic pruritic inflammatory skin disease. We report the first microbiome study and new insights on the relationship between skin microbiota variation and AD susceptibility in a population sample from Egypt. We characterized the skin microbiome in 75 patients with AD and 20 healthy controls using Illumina MiSeq sequencing of 16S rRNA gene. Overall, bacterial diversity of skin microbiome in patients with AD was less than those of the healthy subjects. Genus level analysis revealed significant abundance variations by age, disease severity, locality, or immune response. Among these genera, Streptococcus , Cutibacterium , and Corynebacterium appeared to be specific signatures for AD in children, adolescents, and adults, respectively, while Staphylococcus was noted as a potential biomarker candidate for AD. Additionally, functional potential of metagenomes shifted the overall metabolic pathways to participate in the exacerbation of disease. Total immunoglobulin E (IgE) levels were positively correlated with relative enrichment of certain Staphylococcus aureus subspecies. Finally, AD-related differences in skin bacterial diversity appeared to be in part linked to the serum IgE level. These new observations attest to the promise of microbiome science and metagenomic analysis in AD specifically, and clinical dermatology broadly.