P. aeruginosa is one of the most metabolically versatile bacteria having the ability to survive in multiple environments through its accessory genome. An important hallmark of P. aeruginosa is the high level of antibiotic resistance, which often makes eradication difficult and sometimes impossible. Evolutionary forces have led to this bacterium to develop high antimicrobial resistance with a variety of elements contributing to both intrinsic and acquired resistance. The objectives were to genetically and phenotypically characterizer P. aeruginosa strains isolated from companion animals of different species. We characterized a collection of 39 P. aeruginosa strains isolated from infected animals. The genetic characterization was in relation to chromosomal profile by PFGE; content of virulence gene; presence of genomic islands (GIs); genes of the cytotoxins exported by T3SS: exoU, exoS, exoT and exoY; and type IV pili allele. The phenotypic characterization was based on patterns of susceptibility to different antimicrobials. Each strain had a PFGE profile, a high virulence genes content, and a large accessory genome. However, most of the strains presented high sensitivity to almost all antimicrobials tested, showing no acquired resistance (no β-lactamases). The exception to this lack of resistance was seen with penicillin. P. aeruginosa could be a naturally sensitive bacterium to standard antimicrobials but could rapidly develop intrinsic and acquired resistance when the bacterium is exposed to pressure exerted by antibiotics, as observed in hospital settings.

Helicobacter pylori can persist intracellularly, offering protection against the immune system and antimicrobial treatments, which promote chronic infection. Previous studies revealed that the virulence-associated protein D ( vapD ) gene is transcriptionally induced during H. pylori intracellular infection and was associated with bacterial persistence, as deletion of vapD impairs bacterial intracellular survival. However, whether VapD protein is expressed and localized during intracellular infection had not been demonstrated. The aim of this study was to detect the VapD protein when H. pylori is inside eukaryotic cells. Polyclonal antibodies against VapD and immunofluorescence microscopy were used to detect the VapD expression in co-cultures of H. pylori strain 26695 and AGS cells. The H. pylori strain Tx30a, which lacks the vapD gene, was used as a negative control. VapD expression was detected exclusively in AGS cells infected with strain 26695. Confocal microscopy confirmed the intracellular localization of the VapD signal, which coincided with the localization of H. pylori within AGS cells. In addition, a high proportion of H. pylori -infected AGS cells were positive for VapD signal. Together, these results provide first direct evidence of VapD expression during H. pylori intracellular infection and extend previous transcriptional and genetic studies by confirming VapD production at the protein level, supporting its association with the intracellular state of H. pylori .

Background: Candida species are common causes of nosocomial infections. Candida parapsilosis has emerged as an important pathogen . Mortality rates associated with invasive C. parapsilosis infections range from 14.5% to 47%, with azole resistance estimated between 4% and 15%. Resistance mechanisms include mutations in ERG11 that diminish azole binding, upregulation of ergosterol biosynthesis genes due to mutations in regulatory factors like UPC2 and NDT80 , and increased efflux pump activity. Methods: Thirty clinical strains of the C. parapsilosis complex were isolated from bloodstream cultures, biopsies and catheter tips from hospitalised patients from a major rehabilitation centre in Mexico between June 2011 and August 2016. Minimum inhibitory concentrations for fluconazole, voriconazole, itraconazole, caspofungin, micafungin, anidulafungin and amphotericin B were determined using the broth microdilution method. Whole genome sequencing was conducted using Illumina technology, with subsequent assembly and annotation. Analyses included antifungal resistance variant screening, SNP distance, average nucleotide identity and phylogenetic comparisons with publicly available genomes. Results: Most strains (96.7%, 29/30) were identified as C. parapsilosis sensu stricto, predominantly isolated from blood. Thirty‐three percent of isolates showed phenotypic resistance to fluconazole. The SNP‐distance and maximum‐likelihood phylogenetic analyses revealed two distinct haplotypes and the genotype 1: ERG11 ^WT/Y132F , CDR1 ^{I1287V/I1287V} and UPC2 ^WT/N455D was the most represented (8/10 isolates). Conclusions: C. parapsilosis sensu stricto was the predominant species isolated, with a notable proportion exhibiting resistance to FLU and VOR. The Y132F variant in the ERG11 gene was present in most sequenced isolates.