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Salmonella1,4, [5],12:i:- is one of the most prevalent serovars associated with gastroenteritis in several countries, including Brazil. However, few studies have analyzed the virulence potential of this variant in this country. Therefore, this study aimed to characterize S.1,4, [5],12:i:- strains isolated in Southeast Brazil. To this end, 113 S.1,4, [5],12:i:- strains isolated from different sources between 1983 and 2020 were analyzed. For all strains, the frequencies of 11 virulence genes were investigated using PCR and the molecular typing was performed using pulsed-field gel electrophoresis (PFGE). Furthermore, 40 strains isolated from human and non-human sources were characterized by survival under acid and oxidative stress, and virulence analysis in Galleria mellonellawas performed for 20 selected strains. All virulence genes were detected in more than 91% of the strains. The studied strains were grouped into four clusters using PFGE. Most strains were present in one cluster, named PFGE-A, with a genetic similarity of ≥ 79.5%. All 40 strains survived acid stress after 10 min and 1 h of exposure. Under oxidative stress, all 40 strains survived after 10 min, and 36 survived after 1 h of exposure. In the G. mellonellaassay, nine isolates from non-human sources and six isolates from human showed high-to-intermediate virulence profiles. In conclusion, the pathogenic potential of the strains studied was corroborated by the high frequency of all the virulence genes identified. The PFGE results suggested that most strains belonged to one main cluster that has been prevailing in the São Paulo State, Brazil. The S. 1,4, [5],12:i:- strains isolated from human and non-human sources successfully survived the unfavorable conditions in the human gastrointestinal tract. Finally, strains isolated from non-human sources showed a higher proportion of isolates with high to intermediate virulence profiles in G. mellonellathan in human isolates, suggesting a possible difference between isolates from different origins.

Identification of nonfermenting Gram-negative bacteria (NFGNB) of cystic fibrosis patients is hard and misidentification could affect clinical outcome. This study aimed to propose a scheme using polymerase chain reaction to identify NFGNB. This scheme leads to reliable identification within 3 days in an economically viable manner when compared to other methods.

This study evaluated the salivary concentrations of lactoferrin (Lf) in HIV-seropositive and -seronegative subjects correlating these levels with the incidence of periodontal disease, quantity of Candida spp and systemic condition of the HIV-seropositives (viral load and T lymphocytes CD-4 count and antiretroviral therapy). Whole saliva samples were obtained from 109 subjects who were divided into four groups according to the extent of their HIV infection and their periodontal condition. The salivary Lf concentrations were determined by a standard enzymelinked immunosorbent assay and the quantification of Candida spp. was obtained from all subjects. Among the HIV- participants, higher concentrations of Lf were found in individuals with periodontal diseases (p<0.0001). A similar result was found for HIV participants (p<0.0001). No correlation was found between the concentration of salivary Lf and the quantification of Candida spp or between the Lf concentration and the systemic condition of the HIV+ subjects. The existence of periodontal diseases can modulate an early inflammatory process in the oral mucosa by increasing the expression of Lf, where Lf can act as an antibacterial peptide in HIV- and HIV+ patients. These results suggest that Lf is a possible marker for periodontal diseases in immunocompetent and immunocompromised subjects.