Microbiology Research

Helicobacter pylori is a gastric pathogen that induces chronic gastritis, which may progress to neutrophilic activity, glandular atrophy, intestinal metaplasia, and gastric carcinoma. The aim of this study was to evaluate H. pylori-induced tissue damage. A total of 602 gastric biopsy samples were collected, categorized, and analyzed using hematoxylin and eosin and Giemsa staining, followed by molecular confirmation through PCR targeting the species-specific 16S rRNA gene. H. pylori density and histopathological features were evaluated and graded according to the updated Sydney classification system. H. pylori was detected in 55% (n = 334) of cases, and the antrum (50.83%, p < 0.00001) was the predominant site. A slightly higher prevalence was observed in females, accounting for 56.9% compared to males at 43.1%, which was attributed to sociocultural exposure differences. Individuals aged 11–40 years accounted for 58.3% (n = 195), highlighting early-age acquisition of infection. H. pylori infection was significantly linked to moderate-to-severe inflammation (63.2%, p < 0.00001) and neutrophilic activity (53.3%, p < 0.00001). Intestinal metaplasia and atrophy were infrequent, present in 0.6% (95% CI, 0.02, p = 0.149) and 0.9% (95% CI, 0.05, p = 0.430) of individuals. H. pylori infection causes chronic inflammation and neutrophilic infiltration of the stomach mucosa. Early identification and histopathological examination are essential in assessing H. pylori-related gastric pathology.

Staphylococcus spp. are potential pathogens classified into more than 50 species, frequently presenting antimicrobial resistance (AMR) to several drugs. The present study aimed to identify the Staphylococcus species and their AMR in staphylococci isolated from healthy companion animals (pets) in southern Brazil. A total of 78 presumptive Staphylococcus sp. isolates (from 48 dogs and 30 cats) were obtained in a period of five years (2018–2022). All isolates were analyzed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-ToF) and tested with a panel of antimicrobials frequently used in pet treatment in Brazil. The results demonstrated that 68 isolates were identified as Staphylococcus spp., including 26 (38.2%) classified as coagulase-positive staphylococci (CoPS) and 42 (61.8%) as coagulase-negative staphylococci (CoNS). CoPS included S. pseudintermedius (n = 20; 29.4%), S. aureus (n = 3; 4.4%), and S. schleiferi (n = 2; 2.9%), while CoNS were S. equorum (n = 12; 17.6%), S. felis (n = 7; 10.3%), S. sciuri (n = 8; 11.8%), S. simulans (n = 4; 5.9%), S. epidermidis (n = 1; 1.5%), S. haemolyticus (n = 1; 1.5%), S. saprophyticus (n = 1; 1.5%), and S. xylosus (n = 1; 1.5%). The remaining eight isolates were identified as Staphylococcus spp. AMR analyses demonstrated that 17 (25%) isolates presented susceptibility to all tested drugs, and 51 (75%) to one or more antimicrobials. Twenty-four (35.6%) isolates were multidrug resistant (MDR), and 13 (19.1%) were methicillin-resistant staphylococci (MRS). S. pseudintermedius was the CoPS most frequently with AMR, including nine (45%) MDR and four (20%) MRS, while S. equorum was the predominant CoNS with AMR, highlighting nine (75%) MDR and four (33.3%) MRS. The Staphylococcus species diversity identified here highlights the importance of studying the microorganisms circulating in healthy companion animals and their characteristics concerning pathogenicity and AMR.

Sapindus mukorrosi (Sm) seeds have been used in Chinese medicine for treating gingival disease, suggesting that Sm may modulate oral bacteria and alleviate gingival inflammation. However, the hydrophobicity of seed oil limits its use in the aqueous oral environment. Therefore, the artificial saliva-infused Sm seed aqueous extract (SMa) was developed and applied to our ex vivo model to test its anti-bacterial effect. Unstimulated whole saliva from seven patients with Stage III/IV, Grade C periodontitis was cultured for 8 h with or without SMa. The bacterial count was measured based on the optical density and bacterial DNA concentration. The salivary microbiome was sequenced via next-generation sequencing over the 16S rRNA gene V3-V4 hypervariable regions. The bacterial DNA concentration in the SMa group was significantly lower than the Without-SMa group after 6 to 8 h of culture. No significant difference in alpha and beta diversity was observed between the two groups. The relative abundance of Porphyromonas was reduced, while that of Veillonella was elevated in the SMa group compared to the Without-SMa group. The findings indicated that the antibacterial effects of SMa are manifested primarily through bacterial growth inhibition, with the minor modulation of specific taxa.