Virulence determinants in vancomycin-resistant Enterococcus faecium vanA isolated from different sources at University Hospital of Londrina, Paraná, Brazil

Assessing the pollution and ecotoxicological status of the Iguaçu River, southern Brazil: A review

The degradation of water resources available for human consumption is increasing with the continuous release of chemicals into aquatic environments and their inefficient removal in wastewater treatment. Several watersheds in Brazil, such as the Iguaçu River, are affected by multiple sources of pollution and lack information about their pollution status. The Iguaçu River basin (IRB) has great socioeconomic and environmental relevance to both the supply of water resources and its considerable hydroelectric potential, as well as for the high rate of endemism of its ichthyofauna. Also, the IRB is home to large conservation units, such as the Iguaçu National Park, recognized by UNESCO as a natural World Heritage Site. Thus, this article discusses the chemical pollution in the IRB approaching: (i) the main sources of pollution; (ii) the occurrence of inorganic and organic micropollutants; (iii) the available ecotoxicological data; and (iv) the socioeconomic impacts in three regions of the upper, middle, and lower IRB. Different studies have reported relevant levels of emerging contaminants, persistent organic pollutants, toxic metals, and polycyclic aromatic hydrocarbons detected in the water and sediment samples, especially in the upper IRB region, associated with domestic and industrial effluents. Additionally, significant concentrations of pesticides and toxic metals were also detected in the lower IRB, revealing that agricultural practices are also relevant sources of chemicals for this watershed. More recently, studies indicated an association between fish pathologies and the detection of micropollutants in the water and sediments in the IRB. The identification of the main sources of pollutants, associated with the distribution of hazardous chemicals in the IRB, and their potential effects on the biota, as described in this review, represent an important strategy to support water management by public authorities for reducing risks to the local endemic biodiversity and exposed human populations. Integr Environ Assess Manag 2024;00:1-26. © 2023 SETAC.

The changing landscape of vancomycin-resistant Enterococcus faecium in Australia: a population-level genomic study

Background

Vancomycin-resistant Enterococcus faecium (VREfm) represent a major source of nosocomial infection worldwide. In Australia, there has been a recent concerning increase in bacteraemia associated with the vanA genotype, prompting investigation into the genomic epidemiology of VREfm.

Methods

A population-level study of VREfm (10 November-9 December 2015) was conducted. A total of 321 VREfm isolates (from 286 patients) across Victoria State were collected and sequenced with Illumina NextSeq. SNPs were used to assess relatedness. STs and genes associated with resistance and virulence were identified. The vanA-harbouring plasmid from an isolate from each ST was assembled using long-read data. Illumina reads from remaining isolates were then mapped to these assemblies to identify their probable vanA-harbouring plasmid.

Results

vanA-VREfm comprised 17.8% of isolates. ST203, ST80 and a pstS(-) clade, ST1421, predominated (30.5%, 30.5% and 37.2%, respectively). Most vanB-VREfm were ST796 (77.7%). vanA-VREfm were more closely related within hospitals versus between them [core SNPs 10 (IQR 1-357) versus 356 (179-416), respectively], suggesting discrete introductions of vanA-VREfm, with subsequent intra-hospital transmission. In contrast, vanB-VREfm had similar core SNP distributions within versus between hospitals, due to widespread dissemination of ST796. Different vanA-harbouring plasmids were found across STs. With the exception of ST78 and ST796, Tn1546 transposons also varied. Phylogenetic analysis revealed Australian strains were often interspersed with those from other countries, suggesting ongoing cross-continental transmission.

Conclusions

Emerging vanA-VREfm in Australia is polyclonal, indicating repeat introductions of vanA-VREfm into hospitals and subsequent dissemination. The close relationship to global strains reinforces the need for ongoing screening and control of VREfm in Australia and abroad.

Draft Genome Sequence of Vancomycin-Resistant Enterococcus faecium UEL170 (Sequence Type 412), Isolated from a Patient with Urinary Tract Infection in a Tertiary Hospital in Southern Brazil

Enterococcus faecium is a leading cause of health care-associated infections, with specific lineages circulating in hospital settings worldwide. Here, we report the draft genome sequence of the multidrug-resistant and biofilm-producing E. faecium UEL170, sequence type 412 (ST412), isolated from an inpatient with a urinary tract infection. This strain is a member of clonal complex 17 (CC17), a globally hospital-associated clone.

Changed epidemiology during intra and interhospital spread of high-risk clones of vanA-containing Enterococcus in Brazilian hospitals

We report changes in the molecular epidemiology of vanA-containing Enterococcus during the intra and interhospital spread of high-risk clones, in Southeastern Brazil. While VRE faecalis predominated during 1998 to 2006, a reversal has been observed in the last years, where VRE faecium belonging to ST114, ST203, ST412, ST478 and ST858 have become endemic.

Antibacterial activity of Limonium brasiliense (Baicuru) against multidrug-resistant bacteria using a statistical mixture design

ETHNOPHARMACOLOGICAL RELEVANCE

Limonium brasiliense (Boiss.) Kuntze (Plumbaginaceae) is commonly known as "baicuru" or "guaicuru" and preparations of its dried rhizomes have been popularly used in the treatment of premenstrual syndrome and menstrual disorder, and as an antiseptic in genito-urinary infections. This study evaluated the potential antibacterial activity of rhizome extracts against multidrug-resistant bacterial strains using statistical mixture design.

MATERIALS AND METHODS

The statistical design of four components (water, methanol, acetone, and ethanol) produced 15 different extracts and also a confirmatory experiment, which was performed using water:acetone (3:7, v/v). The crude extracts and their ethyl-acetate fractions were tested against vancomycin-resistant Enterococcus faecium (VREfm), methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae, all of which have been implicated in hospital and community-acquired infections. The dry residue, total polyphenol, gallocatechin and epigallocatechin contents of the extracts were also tested and statistical analysis was applied in order to define the fit models to predict the result of each parameter for any mixture of components. The principal component and hierarchical clustering analyses (PCA and HCA) of chromatographic data, as well as mass spectrometry (MS) analysis were performanced to determine the main compounds present in the extracts.

RESULTS

The Gram-positive bacteria were susceptible to inhibition of bacterial growth, in special the ethyl-acetate fraction of ternary extracts from water:acetone:ethanol and methanol:acetone:ethanol against, respectively, VREfm (MIC=19µg/mL) and MRSA (MIC=39µg/mL). On the other hand, moderate activity of the ethyl-acetate fractions from primary (except water), secondary and ternary extracts (MIC=625µg/mL) was noted against KPC. The quadratic and special cubic models were significant for polyphenols and gallocatechin contents, respectively. Fit models to dry residue and epigallocatechin contents were not possible. PCA and HCA of the chromatographic fingerprints were disturbed by displacement retention time of some peaks, but the ultraviolet spectra indicated the homogeneous presence of flavan-3-ols characteristic of tannins. The MS confirmed the presence of gallic acid, gallocatechin, and epigallocatechin in extracts, and suggested the presence of monomers and dimers of B- and A-type prodelphinidins gallate, as well as a methyl gallate.

CONCLUSION

Our results showed the antibacterial potential of L. brasiliense extracts against multidrug-resistant Gram-positive bacteria, such as VREfm and MRSA. The statistical design was a important tool to evaluate the biological activity by optimized form. The presence of some phenolic compounds was also demonstrated in extracts.