Evaluation of resistance to low pH and bile salts of human Lactobacillus spp. isolates

There are nearly 100 trillion bacteria in the intestine that together form the intestinal microbiota. They are 'good' bacteria because they help to maintain a physiological balance and are called probiotics. Probiotics must have some important characteristics: be safe for humans, be resistant to the low pH in the stomach, as well as bile salts and pancreatic juice. Indeed, their survival is the most important factor, so that they can arrive alive in the intestine and are able to form colonies, at least temporarily. The aim of our study was the evaluation of resistance of Lactobacillus isolates from fecal and oral swabs compared to that found in a commercial product. Seven strains were randomly chosen: L. jensenii, L. gasseri, L. salivarius, L. fermentum, L. rhamnosus, L. crispatus, and L. delbrueckii. We observed a large variability in the results: L. gasseri and L. fermentum were the most resistance to low pH, while only L. gasseri showed the best survival rate to bile salts. Interestingly, the commercial product did not show tolerance to both low pH and bile salts

ENDOSYMBIONTS OF ENTOMOPATHOGENIC NEMATODES FROM SOUTH ITALY:A PHENOTYPIC STUDY

We examined different Xenorhabdusstrains (five of X. bovieniiand two of X. kozodoii), obtained from EPNisolates belonging to the genus Steinernema(S. feltiae, S. ichnusae, S. apuliae, S. vulcanicum) of different geographicorigin by both genotypic and phenotypic analysis. Common laboratory assays were done for traits such as antibioticresistance, haemolytic activity, lactose utilisation, biofilm production, chosen as the least selectable traits for EPN life-cycle, and thus as (presumably) neutral traits. As selective marker, the activity of the endosymbiont’s toxins was verified inan in vivoassay on G. mellonellalarvae. Genotyping done by 16S partial sequencing was used for identification purposes.Xenorhabdusbovieniiisolates showed a broad phenotypic spectrum; on the other hand, X. kozodoiishowed a less degreeof phenotypic variation, reduced ability of biofilm production and conspicuous β-galactosidase activity. However, all thestrains were able to kill G. mellonellalarvae with high efficiency

Retrospective Observational Study on Microbial Contamination of Ulcerative Foot Lesions in Diabetic Patients

According to recent studies, there are almost 435 million people worldwide with diabetes mellitus. It is estimated that of these 148 million will develop Diabetic foot ulcers (DFUs) during their lifetime, of which 35 to 50% will be infected. In this scenario, the presence and frequency of pathogenic microorganisms and their level of susceptibility to the most frequent classes of antibiotics used to treat this pathological condition from patients with DFUs admitted to the outpatient clinic of vascular surgery of the Federico II University Hospital of Naples from January 2019 to March 2021 were investigated. Furthermore, the diabetic population characteristics under study (i.e., general, clinical, and comorbidities) and the pathogenic bacteria isolated from lesions were also considered. Bacterial strains poorly susceptible to antibiotics were more frequent in polymicrobial infections than in monomicrobial infections. β-Lactams showed the highest levels of resistance, followed by fluoroquinolones, aminoglycosides, and finally macrolides. The main findings of the study demonstrated that the occurrence of resistant microorganisms is the dominant factor in ulcer healing; thus it is essential to investigate the antibiotics’ susceptibility before setting antibiotic therapy to avoid inappropriate prescriptions that would affect the treatment and increase the development and spread of antibiotic resistanc

Do Ocular Fluids Represent a Transmission Route of SARS-CoV-2 Infection?

The spread of the new SARS-CoV-2 is marked by a short timeline. In this scenario, explaining or excluding the possible transmission routes is mandatory to contain and manage the spread of the disease in the community. In the recent pandemic, it is still unclear how coronavirus can end up in ocular fluids. Nevertheless, eye redness and irritation in COVID-19 patients have been reported, suggesting that a possible ocular manifestation of SARS-CoV-2 infection may be conjunctivitis. On the basis of epidemiological data provided by previous SARS-Cove infection, numerous theories have been proposed: (1) conjunctiva as the site of direct inoculation by infected droplets; (2) the nasolacrimal duct as a migration route of the virus to the upper respiratory tract, or (3) haematogenic infection of the tear gland. The demand for further investigations to verify ocular involvement in COVID-19 infection came out from the results of recent meta-analysis studies, so the eye cannot be completely excluded as a transmission route of the infection. Thus, healthcare personnel and all the people that enter in contact with infected or suspected patients must always use the prescribed protective equipment