Trichomonas vaginalis is the etiological agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in world, with 276.4 million new cases each year. T. vaginalis can be naturally infected with Mycoplasma hominis and Trichomonasvirus species. This study aimed to evaluate the prevalence of T. vaginalis infected with four distinct T. vaginalis viruses (TVVs) and M. hominis among isolates from patients in Porto Alegre city, South Brazil. An additional goal of this study was to investigate whether there is association between metronidazole resistance and the presence of M. hominis during TVV infection. The RNA expression level of the pyruvate ferredoxin oxidoreductase (PFOR) gene was also evaluated among metronidazole-resistant and metronidazole-sensitive T. vaginalis isolates. A total of 530 urine samples were evaluated, and 5.7% samples were positive for T. vaginalis infection. Among them, 4.51% were isolated from female patients and 1.12% were from male patients. Remarkably, the prevalence rates of M. hominis and TVV-positive T. vaginalis isolates were 56.7% and 90%, respectively. Most of the T. vaginalis isolates were metronidazole-sensitive (86.7%), and only four isolates (13.3%) were resistant. There is no statistically significant association between infection by M. hominis and infection by TVVs. Our results refute the hypothesis that the presence of the M. hominis and TVVs is enough to confer metronidazole resistance to T. vaginalis isolates. Additionally, the role of PFOR RNA expression levels in metronidazole resistance as the main mechanism of resistance to metronidazole could not be established. This study is the first report of the T. vaginalis infection by M. hominis and TVVs in a large collection of isolates from South Brazil.

Trichomonas vaginalis is the causative agent of trichomonosis, the most common non-viral sexually transmitted disease. Infection with this protozoan may have serious consequences, especially for women. Currently, 5-nitroimidazole drugs are the treatment of choice for trichomonosis, but the emergence of resistance has limited the effectiveness of this therapy. In this context, this study aimed to evaluate the anti-T. vaginalis activity of marine-associated fungi found in the South Brazilian Coast. A total of 42 marine-associated fungal species (126 filtrate samples) isolated from 39 different marine organisms, mainly sponges, were selected to be screened against T. vaginalis. Of these, two filtrate samples from Hypocrea lixii F02 and Penicillium citrinum F40 showed significant growth-inhibitory activity (up to 100%) against ATCC 30236 and fresh clinical isolates, including a metronidazole-resistant isolate. Minimum inhibitory concentration (MIC) values of H. lixii F02 and P. citrinum F40 samples for all isolates tested, including the metronidazole-resistant isolate, were 2.5 mg/mL. The kinetic growth curve showed that the filtrate samples were able to reduce the density of parasites to zero within 24 h of incubation, which was confirmed by microscopy. Both fungal filtrate samples exhibited no hemolytic activity, and the P. citrinum F40 filtrate sample showed low cytotoxicity against Vero cells. These data suggest that marine-associated fungi from the South Brazilian Coast may produce potential candidates for further investigation and possible use in the treatment of metronidazole-resistant trichomonosis.

Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease worldwide. Actually, the infection treatment is based on 5-nitroimidazole drugs. However, an emergent number of resistant isolates makes important the search for new therapeutic arsenal. In this sense, the investigation of plants and their metabolites is an interesting approach. In the present study, the anti-T. vaginalis activity of 44 aqueous extracts from 23 Caatinga plants used in folk medicine was evaluated. After screening 44 aqueous extracts from 23 distinct plants against two isolates from ATCC and four fresh clinical isolates, only the Polygala decumbens root extract was effective in reducing significantly the trophozoite viability. The MIC value against all isolates tested, including the metronidazole resistant, was 1.56 mg/mL. The kinetic growth assays showed that the extract was able to completely abolish the parasite density in the first hours of incubation, confirmed by microscopy. In summary, this study describes the first report on the activity of P. decumbens from Caatinga against T. vaginalis, being directly related to the popular knowledge and use.

Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR), one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis.

We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as a tool to characterize coagulase-negative staphylococci (CoNS). Of 253 clinical isolates and 10 control strains, five species and four subspecies were analyzed. All the isolates were identified using conventional phenotypic tests and SDS-PAGE. Discrepant results between these methods, as well as less common species and subspecies, were confirmed by sodA and 16S rDNA gene sequencing. Intraspecies similarities, calculated by the Dice coefficient, were significantly higher when compared to interspecies similarities. The conventional method failed to identify eight (3.2%) molecularly defined and SDS-PAGE-determined isolates. Therefore, SDS-PAGE was able to discriminate between all unidentified or misidentified isolates using a phenotypic method. In addition, SDS-PAGE identified all atypical isolates using biochemistry and CoNS at the subspecies level.