White-nose syndrome, caused by the psychrophilic fungus Pseudogymnoascus destructans, has devastated bat populations across North America. Streptomyces albidoflavus SM254 was previously reported to exhibit antifungal activity against this pathogen, but no comprehensive genomic characterization has been performed to date. Here, we analyzed 34 S. albidoflavus genomes, including the antifungal strain SM254 and 33 publicly available references, to investigate its metabolic potential and functional distinctiveness. Using pangenome reconstruction, phylogenomics, average nucleotide identity, and KEGG pathway profiling, we found that S. albidoflavus SM254 shares high nucleotide identity (> 99%) with five closely related strains but displays a unique combination of complete ethanol fermentation capacity and asparagine biosynthesis deficiency. These traits were exclusive to SM254 and may reflect adaptation to the oxygen-limited, nutrient-variable sediment environment. Functional annotation further revealed high completeness in central energy, redox, and stress-response pathways. Although direct antifungal mechanisms remain to be experimentally validated, S. albidoflavus SM254’s unique metabolic profile and ecological specialization suggest potential relevance in biocontrol contexts.

Recent years have seen an increase in the incidence of acne in adults and teenagers resulting in active research in acne treatment. In the present study, we aimed to improve the anti-acne effects of Hwangryeonhaedok-tang (HHT) through fermentation using a kimchi-derived lactic acid bacterium. Lactiplantibacillus plantarum WiKim0111 (Lpb. plantarum WiKim0111) was selected to ferment HHT due to its strong antioxidant activity and its ability to effectively survive and grow in the HHT medium. The antimicrobial activity of HHT and fermented HHT (FHHT) against Cutibacterium acnes (C. acnes) was determined using an agar well diffusion assay. FHHT exhibited stronger antimicrobial, radical scavenging, and superoxide dismutase activity compared to HHT. RAW 264.7 cells pretreated HHT or FHHT showed significantly lower production of nitric oxide, interleukin (IL) -1β, and IL-6 than lipopolysaccharide -treated cells, with FHHT demonstrating higher efficiency than HHT. Overall, HHT fermented by Lpb. plantarum WiKim0111 displayed enhanced antioxidant and anti-inflammatory properties, as well as greater antibacterial activity against C. acnes compared to unfermented HHT. These findings suggest that FHHT may help mitigate acne symptoms by reducing oxidative stress, modulating inflammation, and directly inhibiting the growth of C. acnes. Further in vitro studies focusing on sebum-producing skin cells, as well as clinical trials evaluating the topical or oral application of FHHT, would be valuable to confirm its efficacy and safety in acne treatment.

In the quest for sustainable fuel sources, chitin-based biorefineries are gaining recognition as chitin is the second most abundant bioresource after cellulose. This approach not only provides an effective method for converting shell waste from seafood processing into valuable bioethanol but also helps in waste management. In this study, Bacillus haynesii, a marine isolate, was investigated and this is the first report on optimisation of process parameters for chitinase production from Bacillus haynesii. The One Factor at a Time (OFAT) method was used to optimize process parameters including inoculum age, inoculum size, temperature, pH, and filling volume, with colloidal chitin identified as the best carbon source for the growth of Bacillus haynesii. The Plackett-Burman Design (PBD) was employed to screen media components, followed by optimization using the Taguchi Orthogonal Array method. The media components investigated included glycerol, yeast extract, MnCl2·4H2O, MgSO4·7H2O, NH4Cl, and colloidal chitin. As a result, the optimized media—comprising 7.5 g/L yeast extract, 7.5% (w/v) glycerol, 0.6% (w/v) colloidal chitin, 1.44 g/L MnCl2·4H2O, and 1.2 g/L MgSO4·7H2O—yielded an enzyme activity of 6.85 U/mL with a specific activity of 28.87 U/mg. Furthermore, ethanol production from chitin oligosaccharides by Saccharomyces cerevisiae was quantified using the potassium dichromate oxidation method, achieving a bioethanol concentration of 2.48% v/v from 33.18 g/L of chitin oligosaccharides. These results demonstrate the potential of Bacillus haynesii-derived chitin oligosaccharides as a promising substrate for bioethanol production.

Mistreatment and unsanitary conditions to which trafficked animals are subjected provide an environment conducive to the proliferation and dissemination of pathogens. The Centros de Triagem de Animais Silvestres (CETAS - Wild Animal Screening Centers), which receive trafficked animals, aim to release them back into the wild, thus making the investigation of pathogens essential. The objective of this study was to conduct an epidemiological study of infections by Chlamydia psittaci and Circovirus in psittacines from wildlife trafficking housed at a CETAS in Bahia. Cloacal swab and blood samples were collected from 135 psittacines, both residents and newly arrived in quarantine, housed at the CETAS in Vitória da Conquista, Bahia. The presence of pathogens was determined by conventional PCR. The PCRs consisted of amplifying the opmA gene and ORF1 to detect C. psittaci and Circovirus, respectively. For C. psittaci, three (2.2%) animals were diagnosed as positive, then treated with antibiotics, retested, and included in the CETAS population after testing negative for the bacterium. Among the 135 psittacines evaluated, 22 (16%) showed feathering abnormalities despite testing negative for Circovirus. This research was the first epidemiological survey of Circovirus infection in psittacines in Bahia and improved the sanitary safety of wildlife release programs.

Aeromonas inhabit diverse aquatic habitats and are recognized as both opportunistic and primary pathogens of fish and humans. This study delineates the biochemical and gyrB sequence-based molecular identification of 14 Aeromonas strains isolated from aquatic environments in Kerala, India, identifying them as A. dhakensis (50%), A. hydrophila (28.6%), and A. jandaei (21.4%). These strains exhibit a high prevalence of virulence genes (act, flaA, ser, gcat, lip, and ela) implicated in pathogenesis in both fish and humans. These findings underline the emergence of A. dhakensis, often misidentified as A. hydrophila, as a potential pathogen, highlighting the necessity for comprehensive identification methods. Significantly, all strains demonstrated beta-hemolysis and moderate to strong biofilm formation, enhancing their infectivity potential. Moreover, all isolates exhibited multidrug resistance, with a multiple antimicrobial resistance (MAR) index ranging from 0.39 to 0.56, and a significant presence of class 1 (500–1100 bp) and class 2 (250–700 bp) integrons, indicating their potential risk to both fish and human populations. Our results underscore the role of aquatic environment as a repository for virulent and multidrug-resistant Aeromonas spp., emphasizing the imperative for prudent antimicrobial usage and regular monitoring of antimicrobial resistance (AMR) in these environments.

The coronavirus disease-2019 (COVID-19) pandemic has affected different sectors of society, and healthcare workers have been particularly impacted. This study aimed to describe the clinical, epidemiological, and molecular characteristics of SARS-CoV-2 infections among healthcare workers in Evandro Chagas Institute, a research reference center in Brazil, from October 2020 to July 2022. 845 samples were collected from individuals who presented clinical symptoms of respiratory infection. Nasopharyngeal positive samples were submitted through genome sequencing. Clinical, epidemiological, and the SARS-CoV-2 lineages (or variants) were analyzed. SARS-CoV-2 positivity was detected in 31.8% (269/845) of samples with a higher prevalence of females (60.2%). The highest SARS-CoV-2 positivity rates were reported in March 2021 (39%), January 2022 (65%), and July 2022 (56%). On clinical symptoms, arthralgia, chills, and diarrhea were statistically significantly detected in 2020; fever, runny nose, and arthralgia in 2021; runny nose, and cough in 2022. On molecular analysis of SARS-CoV-2, 66 samples (25.3%, 66/269) were sequenced and the most prevalent lineage was the Omicron, representing 57.6%. Studies on the epidemiological and clinical characteristics of HCW are essential to propose control measures and work management since research centers play a major role in surveillance to identify and monitor infectious diseases.

Lactobacillus casei Zhang (Lac.z), isolated from traditional sour horse milk in Inner Mongolia, can alleviate various diseases and promote health. Our previous studies found that pretreatment with live Lac.z (L-Lac.z) could significantly attenuate acute kidney injury and delay the progression of chronic renal fibrosis. However, it is unknown whether these effects could be maintained by pasteurized Lac.z (P-Lac.z). Mouse models of acute kidney injury and chronic renal fibrosis induced by renal bilateral ischemia-reperfusion (BIR) surgery were treated with L-Lac.z or P-Lac.z by gavage. Serum and kidney samples were collected to analyze the extent of renal injury and fibrosis, and proteomics was used to explore the potential mechanisms underlying the differences in the effects of the two forms of Lac.z. The results revealed that treatment with L-Lac.z led to a reduction in serum urea nitrogen levels and in less renal tubular injury and subsequent renal fibrosis after BIR-induced renal injury, whereas these effects were not observed in the P-Lac.z group. Proteomic analysis revealed 19 up-regulated proteins and 39 down-regulated proteins in the P-Lac.z group, and these gene products were associated with growth and stress resistance. The specific nephroprotective effects of L-Lac.z may be independent of the interaction of live probiotics with the host.

The evolution, survival, and adaptation of microbes are consequences of gene duplication, acquisition, and divergence in response to environmental challenges. In this context, enzymes play a central role in the evolution of organisms, because they are fundamental in cell metabolism. Here, we analyzed the enzymatic repertoire in 6,467 microbial genomes, including their abundances, and their associations with metabolic maps. We found that the enzymes follow a power-law distribution, in relation to the genome sizes. Therefore, we evaluated the total proportion enzymatic classes in relation to the genomes, identifying a descending-order proportion: transferases (EC:2.-), hydrolases (EC:3.-), oxidoreductases (EC:1.-), ligases (EC:6.-), lyases (EC:4.-), isomerases (EC:5.-), and translocases (EC:7-.). In addition, we identified a preferential use of enzymatic classes in metabolism pathways for xenobiotics, cofactors and vitamins, carbohydrates, amino acids, glycans, and energy. Therefore, this analysis provides clues about the functional constraints associated with the enzymatic repertoire of functions in Bacteria and Archaea.

Acinetobacter baumannii belongs to the ESKAPE group. It is classified as a critical priority group by the World Health Organization and a global concern on account of its capacity to acquire and develop resistance mechanisms to multiple antibiotics. Data from the United States indicates 500 deaths annually. Resistance mechanisms of this bacterium include enzymatic pathways such as ß-lactamases, carbapenemases, and aminoglycoside-modifying enzymes, decreased permeability, and overexpression of efflux pumps. A. baumannii has been demonstrated to possess efflux pumps, which are classified as members of the MATE family, RND and MFS superfamilies, and SMR transporters. The aim of our work was to assess the distribution of efflux pumps and their regulatory gene expression in clinical strains of A. baumannii isolated from burned patients.MethodsFrom the Clinical Microbiology Laboratory at the Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra collection in Mexico, 199 strains were selected. Antibiotics susceptibilities were performed by broth microdilutions to determine minimal inhibitory concentrations. Phenotypic assays with efflux pump inhibitors were conducted using carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and phenylalanine-arginine ß-naphthylamide (PAßN) in conjunction with amikacin, ceftazidime, imipenem, meropenem and levofloxacin. A search was conducted for structural genes that are linked to efflux pumps, and the relative expression of the adeR, adeS, and adeL genes was analyzed.ResultsAmong a total of 199 strains, 186 exhibited multidrug resistance (MDR). Fluoroquinolones demonstrated the highest resistance rates, while minocycline and amikacin displayed comparatively reduced resistance rates (1.5 and 28.1, respectively). The efflux activity of fluorquinolones exhibited the highest phenotypic detection (from 85 to 100%), while IMP demonstrated the lowest activity of 27% with PAßN and 43.3% with CCCP. Overexpression was observed in adeS and adeL, with adeR exhibiting overexpression.Concluding that clinical strains of A. baumannii from our institution exhibited efflux pumps as one of the resistance mechanisms.