In treacherous waters: detection of colistin-resistant bacteria in water and plastic litter from a recreational estuary.

Colistin resistance poses a major therapeutic challenge and resistant strains have now been reported worldwide. However, the occurrence of such bacteria in aquatic environments is considerably less understood. This study aimed to isolate and characterize colistin-resistant strains from water and plastic litter collected in an urban recreational estuary. Altogether, 64 strains with acquired colistin resistance were identified, mainly Acinetobacter spp. and Enterobacter spp. From these, 40.6% were positive for at least one mcr variant (1-9), 26.5% harbored, extended-spectrum beta-lactamases, 23.4% harbored, sulfonamide resistance genes, and 9.3% harbored, quinolone resistance genes. merA, encoding mercury resistance, was detected in 10.5% of these strains, most of which were also strong biofilm producers. The minimum inhibitory concentration toward colistin was determined for the mcr-positive strains and ranged from 2 to ≥512 µg ml-1. Our findings suggest that Gram-negative bacteria highly resistant to a last-resort antimicrobial can be found in recreational waters and plastic litter, thereby evidencing the urgency of the One Health approach to mitigate the antimicrobial resistance crisis.

Antimicrobial resistance and biotechnological potential of plastic-associated bacteria isolated from an urban estuary.

Plastics have quickly become one of the major pollutants in aquatic environments worldwide and solving the plastic pollution crisis is considered a central goal of modern society. In this study, 10 different plastic samples, including high- and low-density polyethylene and polypropylene, were collected from a deeply polluted urban estuary in Brazil. By employing different isolation and analysis approaches to investigate plastic-associated bacteria, a predominance of potentially pathogenic bacteria such as Acinetobacter, Aeromonas, and Vibrio was observed throughout all plastic samples. Bacteria typically found in the aquatic environment harboured clinically relevant genes encoding resistance to carbapenems (blaKPC ) and colistin (such as mcr-3 and mcr-4), along with genetic determinants associated with potentially active gene mobilization. Whole genome sequencing and annotation of three plastic-associated Vibrio strains further demonstrated the carriage of mobile genetic elements and antimicrobial resistance and virulence genes. On the other hand, bacteria isolated from the same samples were also able to produce esterases, lipases, and bioemulsifiers, thus highlighting that the plastisphere could also be of special interest from a biotechnological perspective.

The biotechnological potential of Aeromonas: a bird's eye view.

The genus Aeromonas comprises Gram-negative bacilli widely distributed in aquatic habitats that can also be found in the terrestrial environment and in close association with humans and animals. Aeromonas spp. are particularly versatile bacteria, with high genomic plasticity and notable capacity to adapt to different environments and extreme conditions. On account of being mostly associated with their pathogenic potential, research on the biotechnological potentialities of Aeromonas spp. is considerably scarce when compared to other bacterial groups. Nonetheless, studies over the years have been hinting at several interesting hidden potentialities in this bacterial group, especially with the recent advances in whole-genome sequencing, unveiling Aeromonas spp. as interesting candidates for the discovery of novel industrial biocatalysts, bioremediation strategies, and biopolyester production. In this context, the present study aims to provide an overview of the main biotechnological applications reported in the genus Aeromonas and provide new insights into the further exploration of these frequently overlooked, yet fascinating, bacteria.

Delving into the Mechanisms of Sponge-Associated Enterobacter against Staphylococcal Biofilms.

Staphylococci are one of the most common causes of biofilm-related infections. Such infections are hard to treat with conventional antimicrobials, which often lead to bacterial resistance, thus being associated with higher mortality rates while imposing a heavy economic burden on the healthcare system. Investigating antibiofilm strategies is an area of interest in the fight against biofilm-associated infections. Previously, a cell-free supernatant from marine-sponge-associated Enterobacter sp. inhibited staphylococcal biofilm formation and dissociated the mature biofilm. This study aimed to identify the chemical components responsible for the antibiofilm activity of Enterobacter sp. Scanning electron microscopy confirmed that the aqueous extract at the concentration of 32 µg/mL could dissociate the mature biofilm. Liquid chromatography coupled with high-resolution mass spectrometry revealed seven potential compounds in the aqueous extract, including alkaloids, macrolides, steroids, and triterpenes. This study also suggests a possible mode of action on staphylococcal biofilms and supports the potential of sponge-derived Enterobacter as a source of antibiofilm compounds.

Genomic Chaos (Multiple Copy Number Variations and Structural Reorganization) Detected in Two Prenatal Cases.

The use of new technologies in the routine diagnosis of constitutional abnormalities, such as high-resolution chromosomal microarray and next-generation sequencing, has unmasked new mechanisms for generating structural variation of the human genome. For example, complex chromosome rearrangements can originate by a chromosome catastrophe phenomenon in which numerous genomic rearrangements are apparently acquired in a single catastrophic event. This phenomenon is named chromoanagenesis (from the Greek "chromo" for chromosome and "anagenesis" for rebirth). Herein, we report 2 cases of genomic chaos detected at prenatal diagnosis. The terms "chromothripsis" and "chromoanasynthesis" and the challenge of genetic counseling are discussed.

A New Case with Corpus Callosum Abnormalities, Microcephaly and Seizures Associated with a 2.3-Mb 1q43-q44 Deletion.

1q44 deletion is a rare syndrome associated with facial dysmorphism and developmental delay, in particular related with expressive speech, seizures, and hypotonia (ORPHA:238769). Until today, the distinct genetic causes for the different symptoms remain not entirely clear. We present a patient with a 2.3-Mb 1q44 deletion, including AKT3, ZBTB18, and HNRNPU, who shows microcephaly, developmental delay, abnormal corpus callosum, and seizures. The genetic findings in this case and a review of the literature spotlight a region between 243 Mb and 245 Mb on chromosome 1q related to the genesis of the typical symptoms of 1q44 deletion.

Hiding in Plain Sight: Characterization of Aeromonas Species Isolated from a Recreational Estuary Reveals the Carriage and Putative Dissemination of Resistance Genes.

Antimicrobial resistance (AMR) has become one of the greatest challenges worldwide, hampering the treatment of a plethora of infections. Indeed, the AMR crisis poses a threat to the achievement of the United Nations' Sustainable Development Goals and, due to its multisectoral character, a holistic approach is needed to tackle this issue. Thus, the investigation of environments beyond the clinic is of utmost importance. Here, we investigated thirteen strains of antimicrobial-resistant Aeromonas isolated from an urban estuary in Brazil. Most strains carried at least one antimicrobial resistance gene and 11 carried at least one heavy metal resistance gene. Noteworthy, four (30.7%) strains carried the blaKPC gene, coding for a carbapenemase. In particular, the whole-genome sequence of Aeromonas hydrophila strain 34SFC-3 was determined, revealing not only the presence of antimicrobial and heavy metal resistance genes but also a versatile virulome repertoire. Mobile genetic elements, including insertion sequences, transposons, integrative conjugative elements, and an IncQ1 plasmid were also detected. Considering the ubiquity of Aeromonas species, their genetic promiscuity, pathogenicity, and intrinsic features to endure environmental stress, our findings reinforce the concept that A. hydrophila truly is a "Jack of all trades'' that should not be overlooked under the One Health perspective.

Time for a Change! A Spotlight on Many Neglected Facets of Sponge Microbial Biotechnology.

The sponge-microorganism partnership is one of the most successful symbiotic associations exploited from a biotechnological perspective. During the last thirty years, sponge-associated bacteria have been increasingly harnessed for bioactive molecules, notably antimicrobials and cytotoxic compounds. Unfortunately, there are gaps in sponge microbial biotechnology, with a multitude of applications being understudied or ignored. In this context, the current perspective aims to shed light on these underrated facets of sponge microbial biotechnology with a balance of existent reports and proposals for further research in the field. Our overview has showcased that the members of the sponge microbiome produce biomolecules whose usage can be valuable for several economically- relevant and demanding sectors. Outside the exhaustive search for antimicrobial secondary metabolites, sponge-associated microorganisms are gifted producers of antibiofilm, antivirulence and chronic diseases-attenuating substances highly envisaged by the pharmaceutical industry. Despite still at an infant stage of research, anti-ageing enzymes and pigments of special interest for the cosmetic and cosmeceutical sectors have also been reported from the sponge microbial symbionts. In a world urging for sustainability, sponge-associated microorganisms have been proven as fruitful resources for bioremediation, including recovery of heavy-metal contaminated areas, bioleaching processes, and as bioindicators of environmental pollution. In conclusion, we propose alternatives to better assess these neglected biotechnological applications of the sponge microbiome in the hope of sparking the interest of the scientific community toward their deserved exploitation.

Vibrio Species in an Urban Tropical Estuary: Antimicrobial Susceptibility, Interaction with Environmental Parameters, and Possible Public Health Outcomes.

The genus Vibrio comprises pathogens ubiquitous to marine environments. This study evaluated the cultivable Vibrio community in the Guanabara Bay (GB), a recreational, yet heavily polluted estuary in Rio de Janeiro, Brazil. Over one year, 66 water samples from three locations along a pollution gradient were investigated. Isolates were identified by MALDI-TOF mass spectrometry, revealing 20 Vibrio species, including several potential pathogens. Antimicrobial susceptibility testing confirmed resistance to aminoglycosides, beta-lactams (including carbapenems and third-generation cephalosporins), fluoroquinolones, sulfonamides, and tetracyclines. Four strains were producers of extended-spectrum beta-lactamases (ESBL), all of which carried beta-lactam and heavy metal resistance genes. The toxR gene was detected in all V. parahaemolyticus strains, although none carried the tdh or trh genes. Higher bacterial isolation rates occurred in months marked by higher water temperatures, lower salinities, and lower phosphorus and nitrogen concentrations. The presence of non-susceptible Vibrio spp. was related to indicators of eutrophication and sewage inflow. DNA fingerprinting analyses revealed that V. harveyi and V. parahaemolyticus strains non-susceptible to antimicrobials might persist in these waters throughout the year. Our findings indicate the presence of antimicrobial-resistant and potentially pathogenic Vibrio spp. in a recreational environment, raising concerns about the possible risks of human exposure to these waters.

Genomic and in silico protein structural analyses provide insights into marine polysaccharide-degrading enzymes in the sponge-derived Pseudoalteromonas sp. PA2MD11.

Active heterotrophic metabolism is a critical metabolic role performed by sponge-associated microorganisms, but little is known about their capacity to metabolize marine polysaccharides (MPs). Here, we investigated the genome of the sponge-derived Pseudoalteromonas sp. strain PA2MD11 focusing on its macroalgal carbohydrate-degrading potential. Carbohydrate-active enzymes (CAZymes) for the depolymerization of agar and alginate were found in PA2MD11's genome, including glycoside hydrolases (GHs) and polysaccharide lyases (PLs) belonging to families GH16, GH50 and GH117, and PL6 and PL17, respectively. A gene potentially encoding a sulfatase was also identified, which may play a role in the strain's ability to consume carrageenans. The complete metabolism of agar and alginate by PA2MD11 could also be predicted and was consistent with the results obtained in physiological assays. The polysaccharide utilization locus (PUL) potentially involved in the metabolism of agarose contained mobile genetic elements from other marine Gammaproteobacteria and its unusual larger size might be due to gene duplication events. Homology modelling and structural protein analyses of the agarases, alginate lyases and sulfatase depicted clear conservation of catalytic machinery and protein folding together with suitable industrially-relevant features. Pseudoalteromonas sp. PA2MD11 is therefore a source of potential MP-degrading biocatalysts for biorefinery applications and in the preparation of pharmacologically-active oligosaccharides.